BANGLADESH ENTOMOLOGICAL SOCIETY - …bdentsoc.org/wp-content/uploads/2015/02/BJE-23-1.pdf · BANGLADESH ENTOMOLOGICAL SOCIETY ... Taxonomic description should be given in telegraphic

BANGLADESH ENTOMOLOGICAL SOCIETY(Established 1990)

EXECUTIVE COUNCIL FOR 2011-2013

PresidentProf. Dr. Md. Mahbubar Rahman

Senior Vice-President Vice-PresidentDr. Syed Nurul Alam Dr. Md. Jahangir Alam

General Secretary Joint SecretaryDr. Debasish Sarker Prof. Dr. Md. Abdul Latif

Treasurer Publication SecretarySheikh Shamiul Haque Nirmal Kumar Dutta

Members

Dr. Md. Nurul Alam Prof. Dr. Md. Serajul Islam Bhuiyan

Prof. Dr. Md. Shahjahan Mr. A.K.M. Azad

Dr. Syed Md. Zainul Abedin Mr. Rama Prashad Saha

Dr. Shakil Ahmed Khan Dr. Md. Mosharrof Hossain

Dr. Md. Mahir Uddin Mr. Ataur Rahman

BANGLADESH JOURNAL OF ENTOMOLOGYAn Official Publication of Bangladesh Entomological Society

EDITORIAL BOARD

Editor

Members

Member Secretary

Prof. Dr. Md. Zinnatul Alam

Prof. Dr. Md. Mahbubar Rahman

Prof. Dr. Md. Shahjahan

Dr. Debasish Sarker

Dr. Syed Nurul Alam

Nirmal Kumar Dutta

Payments may be made in favour of Bangladesh Entomological Society through Bank draft

or money order. For subscription please write to :

Publication Secretary

Bangladesh Entomological Society

C/O Entomology Division

Bangladesh Agricultural Research Institute

Gazipur-1701, Bangladesh.

Tel. 9257400, 9256404, E-mail: [email protected]

Printed by :

Sowrov Media Products

Phone : 9615624, Cell : 01718419001, E-mail : [email protected]

Acknowledgement

The publication of this issue of the journal has been funded by the Ministry of Science and

Information & Communication Technology, Government of the People's Republic of Bangladesh.

Subscription Rates for the Bangladesh Journal of Entomology

For Institution : Inside Bangladesh- Tk. 500.00 per copy

Outside Bangladesh- Us $ 40.00 per copy

For Individuals : Inside Bangladesh- Tk. 200.00 per copy

Outside Bangladesh- Us $ 20.00 per copy

Bangladesh Entomological Society publishes the Bangladesh Journal of Entomology twice a year

(June and December). The Journal is included in the abstracting and indexing coverage of the

Entomology Abstracts. Zoological Records and CAB Abstracts.

NOTES FOR AUTHORSThe Bangladesh Journal of Entomology publishes original research papers, review articles and scientific notes concerning insects, other arthropods and vertebrate pests of economic importance in agriculture, medical and veterinary fields. Papers on taxonomy and descriptive morphology should primarily concern insects and arthropods from Bangladesh. Papers intended for publication in the Journal must not have been submitted for publication elsewhere. Manuscript will normally be sent to referees for confidential and critical appraisal. The Editorial Board reserves the right to edit all manuscripts as it deems fit. For general guidance authors are urged to pay attention to the following:Manuscript must be typed in standard type size (10 or 12), double-spaced on 28 cm x 21.5 cm paper with 2.5 cm margins all around and on one side of the paper only. The text should not exceed 12 typed pages. Scientific Notes should not exceed four typed pages.Manuscript should generally be organized in the following style and format: Title, Running Title (not more than 10 words), Author(s) Name and address, Abstract, Keywords (not more than six), Introduction, Materials and Methods, Results, Discussion, Acknowledgements (if any), References. For Scientific Note separate Introduction, Materials and Methods etc., are not required but References should be listed as usual and an Abstract added. Taxonomic description should be given in telegraphic styles.Title should be concise but informative. Author(s) Name(s) and address follow the title. Abstract should be carefully prepared in one paragraph but complete in itself and should not exceed 250 words. the first page of the manuscript should contain only Title and the name and address of the author; the second page, the Title and Abstract. Tables must be kept to a minimum and should not be used where text or illustration gives the same information. Tables should be typed on separate sheets and should have a clear and self explanatory caption. All measurements should be in metric units.Drawings and graphs must be in black water-proof ink on drawing or tracing papers of sufficient size and quality to allow reduction to half or more. Only Black and white glossy prints of photographs are acceptable when they become indispensable to the text.To partly cover the rising printing cost, authors are required to pay Taka 600.00 (Tk. 200+400) for full paper (up to 12 typed pages) and Taka 300.00 (Tk. 200+100) for Scientific Note (up to 4 typed pages) for publication in the Journal. Additional pages will be charged at the rate of Taka 100.00 per typed page. The total page of the manuscript should not exceed 20 typed pages for a full paper and 5 typed pages for a Scientific Note.References. Only references cited in the text should be included and arranged in alphabetical order of the author's surname. Title of the Periodical should be abbreviated as in the World List of Scientific Periodicals. The following style should be used.ANON. 2010. BARI Annual Report (2009-10). Bangladesh Agricultural Research Institute, Joydebpur, Gazipur. pp.181-211.AFSANA, N, & ISLAM, Z. 2001. Predation potential of Micraspis discolor Fabricius (Coleoptera: Coccinellidae) on rice leafhopper and planthopper. Bangladesh j. entomol. 11 (1&2), 67-74.DIXON, A.F.G. 2000. Insect Predator-Prey Dynamic, Ladybird Beetle and Biological Control. Cambridge University Press, Cambridge. 257 pp.WALKER, P. T. 1991. Measurement of insect pest population and injury, pp. 19 - 29. In: TENG, P. S. (ed.). Crop loss assessment and pest management. APS Press, St. Paul, Minnesota.Reprints. Authors will be provided 15 reprints free.

Manuscript should be sent in Duplicate to:

EditorBangladesh Journal of Entomology

C/O Entomology DivisionBangladesh Agricultural Research Institute

Gazipur-1701, Bangladesh.Tel. 9257400, 9256404; E-mail: [email protected]

ii

BANGLADESH JOURNAL OF ENTOMOLOGY

Volume 23 Number 1 June 2013

CONTENTS

K. U. AHMED, M. M. RAHMAN, M. Z. ALAM, M. M. HOSSAIN & M. G. MIAH -Development of an effective integrated package for managing jackfruit trunk borer, Batocerarufomaculata ........................................................................................................................................

M. A. MIAH, M. R. ALI, A. HUSNA & M. M. I. MOLLAH - Ffficacy of some botanicals againstpulse beetle, Callosobruchus maculatus (Fab.) on stored green gram, Vigna radiata .......................

NUZHAT ARA, MOSHARROF HOSSAIN & SELINA PARWEEN - Preference between dimilin-treated and untreated food media by Tribolium castaneum (Herbst) larvae ........................................

A. K. M. Z. RAHMAN, M. A. HAQUE & S. N. ALAM - Oviposition and feeding preference ofHelicoverpa armigera (Hubner) on vegetables ...................................................................................

M. S. AHMED, M. A. SARDAR, M. AHMAD & K. H. KABIR - Determination of pyrethroid andorganophosphorus insecticide residue in brinjal samples collected from some selected regions ofBangladesh ...........................................................................................................................................

YONG JUNG KWON, MD RUHUL AMIN & KYI KYI THAN - Effect of diapause on survival andreproductive performance of bumblebee (Bombus terrestris) queens ......................................................

M. A. RAHMAN, M. Z. ALAM, M. R. U. MIAH, M. I. H. MIAN & M. M. HOSSAIN -Biochemical attributes of different sugarcane varieties and their impact on stem borer infestation ...

K. BEGUM, S.N. ALAM, M. Z. ALAM, M. R. U. MIAH, M. I. H. MIAN & M. M. HOSSAIN -Development of an effective mass rearing method for Trichogramma evanescens and T. chilonisusing two different hosts ......................................................................................................................

M. M. H. KHAN - Abundance and diversity of insect pests and natural enemies in coastal ricehabitat ...................................................................................................................................................

Scientific Note

MD. KAMRUL AHSAN, ATAUR RAHMAN KHAN & TASNIMA FERDOUS - Effect ofvitamin-supplementation on the silkworm, Bombyx mori L. ...............................................................

iii

1

11

21

29

39

53

65

79

89

105

*Corresponding Author: E-mail: [email protected]

1

DEVELOPMENT OF AN EFFECTIVE INTEGRATED PACKAGE FORMANAGING JACKFRUIT TRUNK BORER, BATOCERA

RUFOMACULATA*K. U. AHMED1, M. M. RAHMAN2, M. Z. ALAM2

M. M. HOSSAIN3 & M. G. MIAH4

1Tuber Crops Research Centre, Bangladesh Agricultural Research Institute,Gazipur-1701, Bangladesh; 2Department of Entomology, 3Department of

Horticulture, 4Department of Agroforestry and Environment, BangabandhuSheikh Mujibur Rahman Agriculture University, Gazipur-1706, Bangladesh

ABSTRACTA study was conducted to evaluate different integrated packages for managingthe trunk borer, Batocera rufomaculata infesting jackfruit trees in farmer'sjackfruit orchard at Kapasia Upazila under Gazipur district of Bangladesh,during 2009 - 2010 and 2010 - 2011. Among the six packages, P4 (inspection oforchard at 15 days interval + cut-open tunnel with the help of chisel and sharphaft knife + hooking the hole by sharp iron rod + aluminium phosphide placedinto the hole and sealing the hole with bordeaux paste) was the most effectivepackage and ensured the highest number of healed holes tree -1(3.16). Theperformance was the poorest in package P1 (inspection of orchard at 15 daysinterval + cut-opened tunnel with the help of chisel and sharp haft knife andhooking the hole by sharp iron rod) rendering 1.67 healed holes tree-1, whichwere statistically similar to P3 (injection of Ripcord 10 EC@ 1ml liter -1 waterinto the hole by using syringe + sealing the hole with bordeaux paste) and P5 (P1+ P3). Significantly the highest (p < 0.01) % degree of control (M) was 77.78%found in P4. The yield increase was highest in P4 (68.56%), while it was lowestin P3 (18.48%). The cost: benefit ratio was highest (1: 3.23) in P4, while it waslowest in P3 (1: 1.48). Keywords: Jackfruit, trunk borer, Batocera rufomaculata, management.

INTRODUCTIONJackfruit has been named as the national fruit of Bangladesh and is a fruit that

has been in existence for thousands of years. Jackfruit is usually grown as a fruittree among other fruits and forest trees in the Agroforestry system of Bangladesh.It is a very popular tree of the villagers of Bangladesh and also other Asiancountries (Raintree 1993, Anon. 1995). Jackfruit is grown in all the districts of

Bangladesh j. entomol. (2013) 23(1), 1-10 ISSN 1021-1004

Bangladesh but the leading growing areas are high land of greater Dhaka, Savar,Bhaluka, Madhupur, hilly areas of greater Sylhet district, Rangamati andKhagrachhari (Bhuiyan 1999). Hortex Foundation reported Jackfruit as the secondand 17th largest item among the fresh fruits and vegetables exported to UK andMiddle East countries, respectively (Hossain & Bhuyan 2011). The jackfruit treehas many uses other than supply of food. It is also a potential tree for timber,fodder, fuel-wood and soil conservation. In fact, no part of the tree is withoutvalue. Such an important multipurpose tree is heavily attacked by a trunk borer,Batocera rufomaculata, which may kill the full grown tree. A report was publishedin "The Daily Star" on 13 August 2009 that most of the jackfruit trees wereseriously infested by trunk borer in Shreepur upazila as well as Gazipur district.Many of the trees were dying and some trees were already dead (Ahmed 2008).

Several borers are found on jackfruit tree among which Batocera rufomaculataattacks trunk of the tree (Sing 1969, Hill 1975). The larva of trunk borer makeszigzag burrow beneath the bark and tunnel into trunk, main branches and stem,moving upward feeding on the internal tissue. Infested, branches and stem showbored holes. In tropical and subtropical countries of the world, this pest has nowbecome an important economic pest. During the last few years, this pest caused aserious problem in Shreepur and Gazipur districts and its infestation severity wasdiscussed in the National Workshop held on 19 November 2000 (Hossain 2000)and 02 March 2011 (Kabir & Khorsheduzzaman 2011) at Bangladesh AgriculturalResearch Council. Every year loss has occurred due to severe trunk borerinfestation. Unfortunately, very little work regarding management of trunk borerhas been done in Bangladesh. Alam (1974) prescribed regular visit of the orchard,collection and destroying the beetles and larvae and also suggested application ofpara-dichlorobenzene into the holes of borers and sealing up with mud. Chatterjee& Sing (1968) and Singh (1985) reported that pruning of infested branches ofolder trees and fumigation on main stem would be effective in controlling the pest.In particular, information about the control of trunk borer in jackfruit trees in thissubcontinent, including Bangladesh is scanty.

Keeping all the above points in view, the present studies were undertaken fordeveloping an effective integrated management package based on effectivenessand benefit-cost ratio for management of the jackfruit trunk borer.

K. U. AHMED, M. M. RAHMAN, M. Z. ALAM, M. M. HOSSAIN & M. G. MIAH

2

MATERIALS AND METHODSThe study was conducted at farmer's jackfruit orchard in Kapasia Upazila

under Gazipur district during 2009 - 2010 and 2010 - 2011. It was laid out atRCBD with six treatments and six replications. One jackfruit tree was consideredas one replication of a treatment. About 20 to 30 year old trees infested by trunkborer were used. The study comprised the following six treatment packagesincluding control. The treatments were: P1 (inspection of orchard at 15 daysinterval + cut-opened tunnel with the help of chisel and sharp haft knife andhooking the hole by sharp iron rod), P2 (placement of aluminium phosphide intothe hole and sealing the hole with bordeaux paste), P3 (injection of ripcord 10 EC(cypermethrin) @ 1ml liter -1 water into the hole by using syringe and sealing thehole with bordeaux paste), P4 ( P1 + P2), P5 (P1 + P3), P6 ( untreated control).

Data was recorded by investigations of the external features of the holes, thefrass on the ground, the fresh bleeding sap around the holes and the number offresh holes. The hole was counted at 2 m height of each trunk from soil level. Theperformance of each treatment was explained in terms of healing hole andrecovery of the damage of infested trees, increase of yield over control and theBCR. The efficacy of different treatments was classified into four classes I, II, IIIand IV to represent the state of larval activity, with corresponding values (v) of 3,2, 1 and 0 to calculate the degree of control (Sheng-Ying et al. 2009). Grading standard of efficacy of different treatments (Sheng-Ying et al. 2009):External features of the defecator holes Class Value Larval activityNo new holes and old holes had healed, trees which recover damage gradually I 3 Larvae had diedNo new holes, no saw dust on the ground, II 2 Larvae were in a no fresh bleeding sap and frass comatose stateNo new holes, no saw dust on the ground III 1 Larvae became weakbut little bit bleeding sap, fresh frass and caused slight damageNew holes, fresh bleeding sap, fresh IV 0 Larvae were active frass, saw dust on the ground and caused serious damage

Calculation was done by using the following formula: vDegree of control (M) = ---------- x 100 %3

Integrated package for managing jackfruit trunk borer

3

Mean value of the control - Mean value of the treatmentReduction of infestation over control = --------------------------------------------------------------------------------------------------------------x 100

Mean value of the control Net return

Benefit Cost Ratio (BCR) = -------------------------------------------------------------------------------Total management cost

The collected data were analyzed through MSTAT-C software in single factorRCBD, and DMRT was used to separate means.

RESULTS AND DISCUSSIONEfficacy of different integrated packages for healing hole : Results of

different Integrated Pest Management (IPM) packages are presented in Table 1. Asevident from this Table, there were significant differences in the performance ofhealing hole and recovery of the infestation resulting from different packages. Themean number of healed holes tree-1 was significantly (P<0.01) much higher in anypackage as compared to the control. However, P4 (inspection of orchard at 15 daysinterval + cut-opened tunnel with the help of chisel and sharp haft knife andhooking the hole by sharp iron rod + placement of aluminium phosphide into thehole and sealing the hole with bordeaux paste) ensured the highest number ofhealed holes tree-1 (3.16), which was followed by 2.83 in P2 (placement ofaluminium phosphide into the hole and sealing the hole with bordeaux paste). Thelowest number of healed holes tree-1 was 1.67 in P1 (inspection of orchard at 15days interval + cut-opened tunnel with the help of chisel and sharp haft knife andhooking the hole by sharp iron rod), which was statistically identical with P3 (1.83)and P5 (1.83), but significantly differed from control (P6).

In case of effectiveness of treatments expressed in terms of reduction of thenumber of unhealed hole per tree is shown in Table 1, P4 performed significantly(P<0.01) better ensuring the lowest number (0.33) of unhealed hole followed byP2 (1.33). The poorest performance in terms of failure to heal holes tree-1 was inP3 (2.17), which were statistically similar to P1 (2.16) and P5 (1.83). The numberof unhealed holes per tree was the highest in the P6 untreated control plot (3.33).

In case of existing oozing hole as presented in Table 1, P4 ensured the larvaldeath showing the best performance in healing of oozing hole (0.16). On the otherhand, the number of oozing holes tree-1 in P3 [cypermethrin (ripcord 10 EC) 1mlliter-1 water injection to the hole by using syringe] and P5 was 1.00, which wasfollowed by P6 (0.83), P2 (0.67) and P1 (0.50) and. In overall consideration P4 wasthe most effective among the packages.


4

Table 1. Effect of different packages against trunk borer infestation on jackfruittrees during 2010-11

Packages Mean number of Mean number of Mean number of newhealed holes tree-1 unhealed holes tree-1 oozing holes tree-1

P1 1.67 b 2.16 b 0.50 abP2 2.83 ab 1.33 bc 0.67 abP3 1.83 b 2.17 b 1.00 aP4 3.16 a 0.33 c 0.16 bP5 1.83 b 1.83 b 1.00 aP6 0.00 c 3.33 a 0.83 ab

Probability level <0.01 < 0.01 <0.05LSD value 1.092 1.035 0.7445

Means followed by common letter(s) in a column are not significantly different at 5% and 1% levelby DMRT. Values are the averages of six replications. P1 (inspection of orchard at 15 days interval + cut-opened tunnel with the help of chisel and sharphaft knife and hooking the hole by sharp iron rod), P2 (placement of aluminium phosphide into thehole and sealing the hole with bordeaux paste), P3 (injection of ripcord 10 EC (cypermethrin) @1ml liter-1 water into the hole by using syringe and sealing the hole with bordeaux paste), P4 (P1 +P2), P5 (P1 + P3), P6 (untreated control).

Per cent degree of control of trunk borer infestation by different integratedpackages: By using grading standard of control effect, the effect of differentintegrated packages on jackfruit trunk borer was investigated from original recordsof the effect of the control measures shown in Table 2. The state of larvae changedconstantly from the active state (IV) to death (I) under different packages. Resultsclearly indicate the degree of control (M) of different packages based on analysisof variance and DMRT comparisons. The statistically highest (p < 0.01) per centdegree of control (M) was 77.78 % in P4 (P1 + P2), which was statistically identicalwith P2 (66.67 %) and P5 (55.55 %). Per cent degree of control (M) in P3 and P1was 38.89 % and 33.33 %, respectively, which had the poorest performance beingstatistically similar with untreated control (P6). The degree of control (M) oftreated larvae in the intermediate states II and III showed death and their old holeshad healed. Until the treatment applied, the larvae were active, inflicting seriousdamage, as evidenced from fresh frass emanating from old and new holes. The testresults revealed that P4 had significant (p < 0.01) effect in controlling trunk borerlarvae in jackfruit trees. This result also shows clearly the degree of control (M)


5

Table 2. Grading of control effect of different treatments against jackfruit trunkborer

Treated trees with control effects %Packages No. 1 No. 2 No. 3 No. 4 No. 5 No. 6 Degree of Summary

control (M)

P1 II (2) III (1) II (2) III (1) IV (0) IV (0) 33.33 ab(4.645)

P2 I (3) III (1) I (3) I (3) IV (0) II (2) 66.67 a(7.322)

P3 IV (0) II (2) IV (0) II (2) II (2) III (1) 38.89 ab(5.042)

P4 I (3) III (1) II (2) I (3) I (3) II (2) 77.78 a(8.682)

P5 III (1) III (1) III (1) II (2) I (3) II (2) 55.55 a(7.272)

P6 IV (0) IV (0) IV (0) IV (0) IV (0) IV (0) 0.00 b(0.00)

Probability - - - - - - <0.01levelLSD (0.01) - - - - - - 4.981

Means followed by common letter(s) in a column are not significantly different at 1% level byDMRT. Values are the averages of six replications. Figures in parentheses indicate data based onsquare root transformation. P1 - P6: as in table 1.


6

Gradingstandard of thecontrol effect ofdifferenttreatments hasbeen describedearlier inmaterials andmethods section.Roman numberindicatesgrading classand numberwithinparenthesisindicates value.

and reveals a general increase in the effectiveness of the packages P4, P2, and P5although the margins of the increases varied. If this trend were to continue, all ofthe treated larvae would die. The degree of control (M) dropped slightly in P3 andP1 as compared to P4, P2 and P5 because some larvae survived and resumed theiractivity in the interval. The degree of control (M) among these treatments P4, P2and P5 was better than that of P3 and P1. Similar study was conducted for Aprionagermari (Hope) by Sheng-Ying et al. (2009), Liu et al. (1996) and Wang et al.(2004), who reached a conclusion that from the time of inserting the poisonousfumigant to the death of the larvae is a slow process. The treated larvae can changefrom the intermediate state II and III to their death or resume their activity andcontinue to do serious damage. Two scenarios to explain these findings are

conceivable either, the large volume of the tunnel leads to a low concentration ofthe hypertoxic phosphine, which means that the larvae do not die in a short period,but in the end all of the holes of the treated larval tunnel become blocked withbordeaux paste or cow dung and the poisonous environment caused the death ofthe treated larvae. Aluminium phosphide provides a convenient and economicallyfeasible method to control trunk borer larvae. As is generally known, chemicalcontrol is only one part of integrated pest management, applied after the damagehas occurred. In order to protect trees and reduce losses, physical and culturalcontrol methods should be carried out before the emergence of larvae (Dickmannet al. 2001). Table 3. Effect of different integrated packages on yield of jackfruit during 2010-11

Packages Before treatment After treatment Per cent yield Per cent yield (Previous year yield) (Current year yield) increase/decrease increase over Fruit Tree-1 Fruit Tree-1 over previous control (%)

year (%)P1 6.5 8.00 ab 23.08 26.38P2 7.00 9.00 ab 28.57 42.18P3 6.00 7.50 b 25.00 18.48P4 8.00 10.67 a 33.38 68.56P5 7.00 9.16 ab 31.00 44.87P6 7.50 6.33 b -15.60 0

Probability level NS <0.05 - -LSD (0.05) - 2.599 - -

Means followed by common letter(s) in a column are not significantly different at 5% level byDMRT. Values are the averages of six replications. P1 - P6 as in Table 1.

Effect of different integrated packages on the yield of jackfruit: Differentintegrated packages caused significant (P<0.05) increase in yield (fruit stree-1) ofjackfruit over control, which ranged from 18.48 % to 68.56 % and over previousyear ranged from 23.08 % to 33.38 % (Table 3). The yield was the highest in P4(10.67 fruit stree-1) followed by P5 (9.16), P2 (9.00) and P1 (8.00) fruit stree-1,respectively. The yield was the lowest in P3 (7.50 fruit stree-1), which did notsignificantly differ from that of untreated control (P6). Yield decreased by 15.60%in the control plot as compared to the previous year, which indicates infested treemight lose yield drastically if no management action is taken.


7

This is in conformity with Gupta & Sharma (1988) who also observed that ifthe insects are abundant in plantations, it is an indication that multiplication isoccurring in food plants in adjoining area which may continue year after year intrees and after several years of infestation the tree reaches a severe condition ofinfestation if no management practice is applied.

Economic analysis of different integrated packages applied against trunkborer infestation: Economic analysis of different integrated packages appliedagainst trunk borer infestation on jackfruit trees is presented in Table 4. The highestcost: benefit (1: 3.23) was obtained in P4, which was followed by P5 (1: 2.79) andP2 (1: 2.59) while P3 and P1 were 1: 1.48 and 1: 1.77 respectively, which were thelowest. Table 4. Economics of different integrated packages on jackfruit trunk borer

management during 2009-2010 in farmer's orchard at Kapasia.Packages Mean yield Increase *Value of Cost of Benefit Cost:

(Fruits ha-1) in yield increased treatment due to Benefitover control yield (Tk ha-1) treatment(Fruits ha-1) (Tk ha-1) (Tk ha-1)

P1 1128.00 235.47 11773.5 4250 7523.5 1 : 1.77

P2 1269.00 376.47 18823.5 5240 13583.5 1 : 2.59

P3 1057.50 164.97 8248.5 3325 4923.5 1 : 1.48

P4 1504.47 611.94 30597.0 7240 23357.0 1 : 3.23P5 1291.56 399.03 19951.5 5270 14681.5 1 : 2.79P6 892.53 - - - - -

*Average sale price of jackfruit in the wholesale market was Tk 50 per fruit. P1 - P6 as in Table 1.

Relationship between per cent degree of control and yield: The relationshipbetween per cent degree of control and increase in yield was computed (Fig. 1). Alinear regression indicated a positive linear trend between per cent degree ofcontrol and increase in yield. The regression equation y = a + bx, where y = yield,a = 6.1042, b = 0.0516 and x = degree of control. The contribution of theregression (R2 = 0.9036) was 90.36%.


8

REFERENCESANON. 1995. Fruit production manual. Horticulture Research and Development

Project. 60 pp. AHMED, F. U. 2009. Diseased jackfruit trees. The Daily Star, August 13, 2009. ALAM, M. Z. 1974. Insect and mite pests of fruits and fruit trees in Bangladesh

and their control (Revised Edition). Bangladesh Agric. Res. Institute,Directorate of Agriculture (Research and Education) Bangladesh. pp. 1-119.

BHUIYAN, A. J. 1999. Fruit tree management and development, Lift-projectCARE, Bangladesh, 33 pp.

CHATTERJEE, P. N. & SING, P. 1968. Celosterna scabrator Fabricious (Lamiidae:Coleoptera) and new pest of Eucalyptus. Indian Forester. 94, 826-830.

DICKMANN, D. I., ISEBRANDS, J. G., ECKENWALDER, J. E. &RICHARDSON, J. 2001. Poplar Culture in North American. Ottawa: NRCResearch Press. 324 pp.

GUPTA, V. K. & SHARMA, N. K. 1988. Tree Protection. Indian Society of TreeScientists, Solan (H. P.), India, 326 pp.

HOSSAIN, M. M. 2000. Research and development of jack fruit in Bangladesh.Key note paper, presented in the National Workshop on jack fruit, Organizedby Bangladesh Society of Horticultural Science held on Nov. 19, 2000 atBARC Auditorium, Dhaka. 175 pp.


9

HILL, D. S. 1975. Agricultural insect pests of the tropics and their control.Cambridge University press. pp. 446-584.

HOSSAIN, A. M. & BHUYAN, J. A. M. 2011. Insect pests of jackfruit and theirmanagement in Bangladesh-progress, limitations and prospect. Paperpresented in a National workshop held at Bangladesh Agricultural ResearchCouncil in 02 March 2011. 12 pp.

KABIR, K. H. & KHORSHEDUZZAMAN, A. K. M. 2011. Insect pests ofjackfruit and their management in Bangladesh-progress, limitations andprospect. Paper presented in a National workshop held at BangladeshAgricultural Research Council in 02 March 2011. 10 pp.

LIU, S. C., ZHAO, R. L., LU, X. H., ZHU, L. A. & LIU, M. H. 1996. Studies onApriona germari (Hope) control techniques. Shanxi For Sci Technol. 1, 34-36 (in Chinese).

RAINTREE, J. 1993. Documentary Survey on Artocarpus heterophyllus(Jackfruit) in Sri Lanka. Winrock International, Regional Office, Thailand.120 pp.

SINGH, R. 1985. Fruits. National Book Trust, New Delhi, India. 125 pp.SING, R. 1969. Fruits. National Book Trust. New Delhi, India. 115 pp.SHENG-YING, S., JUN-BAO, WEN., MIN CHEN, XIAO-LI HU, FANG LIU &

JING LI. 2009. Chemical control of Apriona germari (Hope) larvae withzinc phosphide sticks. For. Stud. China. 11(1), 9-13.

WANG, Y. S., GUO, W. H. & REN, H. Q. 2004. Studies on Apriona germari(Hope) control techniques in Xuzhou. J. Jiangsu For Sci Technol. 31(1), 26-28 (in Chinese).

(MS received for publication 02 November 2012)


10

*Corresponding Author: Email: [email protected]

11

EFFICACY OF SOME BOTANICALS AGAINST PULSE BEETLE,CALLOSOBRUCHUS MACULATUS (FAB.) ON STORED GREEN

GRAM, VIGNA RADIATA*M. A. MIAH1, M. R. ALI2, A. HUSNA3 & M. M. I. MOLLAH1

1Department of Entomology, 3Department of Biotechnology, Patuakhali Scienceand Technology University, Dumki, Patuakhali-8602; 2Department of

Entomology, Sher-e-Bangla Agricultural University, Dhaka-1207

ABSTRACTInsecticidal efficacy of some botanicals, Neem (Azadiracta indica) oil, Castor(Ricinus communis) oil, Camphor (Cinamomum camphora), Neem leaf powder,Castor leaf powder and Bankolmi (Ipomoea sepiara) leaf powder were tested ongreen gram (Vigna radiata) against pulse beetle, Callosobruchus maculatus inthe laboratory. Among the botanicals, Camphor @ 2 gm kg-1 seeds, Neem oil @8 ml kg-1 seeds and Castor oil @ 8 ml kg-1 seeds performed best in respect ofper cent reduction of oviposition, egg hatching, larval and pupal development,grain damage and grain content loss while partial reduction occurred by Neemleaf powder, Castor leaf powder and Bankolmi leaf powder. The order ofeffectiveness among the botanicals was Camphor > Neem oil > Castor oil >Neem leaf powder > Castor leaf powder > Bankolmi leaf powder. Consideringthe germination of seeds, there was no significant effect of Camphor, Neem oiland Castor oil treated seeds, while considerable germination reduced in Neem,Castor and Bankolmi leaf powder at 5% w/w treated seeds. It indicated that leafpowder of different botanicals was less effective against pulse beetledevelopment compared to the different oils of botanicals.Keywords: Efficacy, Botanicals, Callosobruchus maculatus and Green gram.

INTRODUCTIONPulses are of special nutritional and economic importance due to their

contribution to the diets of millions of people worldwide. Among the pulses, greengram (mungbean), Vigna radiata (L.) Wilczek, is an indigenous legume in SouthAsia. It contains 51% carbohydrate, 26% protein, 4% minerals, 3% vitamins(Yadav et al. 1994). Almost all growers store required quantity of pulse seeds intheir house for growing in next year. The traders also store pulses. Unfortunately,in storage, pulses suffer enormous losses due to bruchid attack which starts either


in the field on the maturing pod and is carried to the stores with the harvested cropsor originates in the storage itself. Three species of pulse beetle, Callosobruchuschinensis Linn., C. analis Fab. and C. maculatus Fab. have been reported fromBangladesh as the pest of stored pulses (Begum et al. 1984, Rahman et al. 1981).Green gram, Vigna radiata appeared to be the most common and suitable host forthe C. maculatus in respect of oviposition, larvae, pupae, adult emergence andgrain content loss (Ali & Rahman 2006). Due to attack of C. maculatus, 55-60%loss in seed weight, 45.50-66.30% loss in protein content and pulse seeds becameunfit for human consumption as well as for planting (Gujar & Yadav 1978). Theextent of damage might be up to 100% in mungbean seed during a period of oneyear in storage (Chowdury 1961).

At present, pest control measures in storage depend on the use of syntheticinsecticides and fumigants. The indiscriminate use of insecticides in the storage,causes insect resistance, toxic residues in food grains (Fishwick 1988),environmental pollution and increasing costs of application. In view of theseproblems safe alternatives of conventional insecticides and fumigants to protectstored grains from insect infestations is essential. The naturally occurring,biologically active botanicals appear to have a prominent role for the developmentof future commercial pesticides not only for increased productivity but for thesafety of the environment and public health. A number of botanicals and theirderivatives have been tested in Bangladesh and other countries particularly againstpulse beetles and have shown promising results (Saxena & Yadav 1983).Botanicals are more readily biodegradable and less toxic to mammals. Moreover,there is no report of pest resurgence due to the use of botanicals pesticides. Thefarmers can produce it easily and buy cheaply. Therefore, the present study wasundertaken to screen some botanicals with a view to explore the insecticidalproperties against pulse beetles in stored green gram.

MATERIALS AND METHODSThe efficacy of some botanicals was evaluated in storage condition in thelaboratory under the Dept. of Entomology, Sher-e-Bangla Agricultural University,Dhaka, Bangladesh during the period from March to October, 2008.Rearing and maintenance of test insects: Test insects (Pulse beetle,Callosobruchus maculatus) used in the present investigation were obtained fromstock cultures in the laboratory of the Deptartment of Entomology, Sher-e-BanglaAgricultural University. Stock culture of C. maculatus was maintained on green

M. A. MIAH, M. R. ALI, A. HUSNA & M. M. I. MOLLAH

12

gram seeds in plastic jars covered with cloth in the same laboratory. One hundredpairs of C. maculatus were introduced into a plastic container (12 cm dia. 14 cmheight) containing 200 gm of de-infested seeds. The mouth of the containers wascovered with perforated plastic lids. The insects were allowed to mate and lay eggsfor 24 hours, after which sieving was done to separate the adult beetles. The greengram seeds with eggs left on the sieve were kept for adult emergence. One-day-old(0-24 hours) adults were used for study. The rearing procedure was repeated indifferent batches to ensure continuous supply of the adults with required eggs. Identification of male and female: Male and female beetles were sorted out undersimple microscope by their antennal characteristics, size and shape of the body. Preparation of seeds: Seeds of green gram (Vigna radiata Walp), variety BarisalLocal (Local variety) were used for the present study as most susceptible hosts toC. maculatus i.e. as food of pulse beetle. Seeds were cleaned and disinfested bykeeping the seeds at 0o C for 14 days prior to use.Test botanicals: Collection and preparation: Six botanicals were used as testinsecticides. Among them, Neem (Azadirachta indica) oil and Castor (Ricinuscommunis) oil were applied @ 8 ml/kg, leaf powder of Neem, Castor andBankolmi (Ipomoea sepiara) were applied @ 5% w/w and Camphor (Cinamomumcamphora) was used @ 2 g/kg. All the botanicals were tested against C. maculatuson the seeds of Barisal local variety as the most susceptible host. Among the tested botanicals, Neem oil, Castor oil and Camphor were bought fromthe local market whereas the leaves of the tested botanicals were collected fromUniversity campus. Collected leaves and seeds were dried under ambient roomtemperature (27°C-34°C) and then ground separately by a hand grinder and sievedthrough a 60-mesh sieve to get fine powder. Insecticidal property test of botanicals on pulse beetle: Two hundred gram(200g) of green gram seeds (Barisal local) were taken separately for eachtreatment in a round plastic pot (12 cm dia. 14 cm height) and specific botanicalswere mixed thoroughly by hand shaking. Ten pairs (male and female) of one dayold healthy adults of C. maculatus were released in each of the plastic pots. Theplastic pot was covered with their lids and kept at room temperature (27°C-34°C)in the laboratory for 45 days. The developmental stages were also observed andthe data were recorded. The weight of the grains was recorded after 50 days ofrelease of pulse beetles.

Efficacy of some botanicals against pulse beetle

13

Determination of seed viability: Germination tests were also done with randomlytaken 100 green gram seeds from each of the treatment at the initial and after 50days of treatment application to evaluate the treatment effects on the viability ofthe seeds and the tests were replicated three times. The seeds were placed in Petri-dish having water soaked blotting paper at the bottom. Then the Petri-dishcontaining green gram seeds were incubated at room temperature and germinationwas estimated by direct count. For recording data, 100 seeds for each treatment were collected randomly fromeach treated pot. From the experiment, data were calculated on differentparameters using the following formula:

No. of eggs per collected sample x Total no. of seeds per poti) Total no. of egg/pot = ----------------------------------------------------------------

Number of seeds per collected sample

No. of eggs hatched in collected sample ii) % egg hatching = ------------------------------------------------------x 100

Total no. of eggs laid in collected sample

No. of alive larvae / pupae in collected sample iii) % larvae / pupae developed = -------------------------------------------------x 100

Total no. of eggs laid in collected sampleNumber of bored seeds

iv) % grain damage = ------------------------------x 100Total number seeds

Weight loss per potv) % grain content loss = ---------------------------------- x 100

Initial wt. of grains per pot

Weight loss per pot = Initial wt. - final weight of grains per pot.Number of germinated seeds

vi) % grain germination = ---------------------------------------x 100Total number of seeds

X2 - X1vii) Per cent infestation reduction over control = --------------- x 100X2

Where, X1 = the mean value of the infestation of treated green gram per potX2 = the mean value of the infestation of untreated green gram per pot

Statistical analysisThe experimental data were analyzed by ANOVA-1 in Completely RandomizedDesign (CRD) with three replications and the means were separated by DMRT.


14

RESULTS AND DISCUSSIONEffects of botanicals on oviposition and egg hatching: Significant differenceswere found in the effects of different botanicals applied against pulse beetle ontheir oviposition and egg hatching (Table 1). It was observed that no eggs werelaid on the Camphor treated green gram, followed by Neem oil (400) and Castoroil (450) in terms of less egg deposition which were statistically similar. Highestnumber of eggs were laid on untreated (control) seeds (17,300 eggs), followed byBankolmi leaf powder (15,400 eggs), Castor leaf powder (13,500 eggs) and Neemleaf powder (10,200 eggs). Highest percent egg deposition reduction (100%) overcontrol was found in Camphor treated green gram seeds followed by Neem oil(97.68%) and Castor oil (97.39%), while the lowest was found in Bankolmi leafpowder (10.98%) treated green gram seeds followed by Castor leaf powder(21.96%) and Neem leaf powder (41.04%). Per cent hatching was highest (88%)in untreated seeds, which was followed by Bankolmi leaf powder (84%), Castorleaf powder (82%) and Neem leaf powder (80%), while the lowest per centhatching was obtained from Neem oil (8%) followed by Castor oil (10%) treatedseeds. Maximum percent hatching reduction over control was obtained fromCamphor (100%), followed by Castor oil (88.63%) and Neem oil (87.90%).Conversely, the lowest of that was observed in case of Bankolmi leaf powder

Table 1. Effect of different botanicals on oviposition and egg hatching ofCallosobruchus maculatus in green gram

Treatments Egg deposition Oviposition Egg Hatching (No.) reduction over Hatching reduction over

control (%) (%) control (%)Neem oil 400 d 97.68 8 c 87.90Castor oil 450 d 97.39 10 c 88.63Camphor 0.00 e 100.00 0 d 100.00Neem leaf powder 10,200 c 41.04 80 b 9.09Castor leaf powder 13,500 b 21.96 82 b 6.80Bankolmi leaf powder 15,400 b 10.98 84 b 4.55Untreated Control 17,300 a - 88 a -

Values are mean of three replications. Means followed by same letter in a column are notsignificantly different (P>0.05) from each other by DMRT.


15


16

(4.55%) followed by Castor leaf powder (6.80%) and Neem leaf powder (9.09%).It was evident from the results that among the botanicals Camphor, Neem oil andCastor oil are more effective against the pulse beetle, C. maculatus in reducingoviposition and hatching. The results were almost similar to the findings of Keitaet al. (2001). They reported that when mixed with stored grains, leaf, seed powderor oil extracts of plants reduced oviposition rate. Effects of botanicals on larval and pupal development: No larvae and pupae ofC. maculatus were developed in Neem oil, Castor oil and Camphor treated greengram (Table 2). As no eggs were found in camphor treated green gram it is obviousthat no larvae and pupae were developed. Though in Neem oil and Castor oil asignificant number of eggs were laid, a very few percent could hatch but could notcontinue their development at larval and pupal stage due to toxic effect of thesebotanicals. Highest percentage of larval and pupal development (86% and 87%)were observed in untreated control treatment, followed by Bankolmi leaf powder(40% and 45%), Castor leaf powder (35% and 37%) and Neem leaf powder (30%and 32%).The highest percent (100%) reduction of larval and pupal developmentover control was found in Neem oil, Castor oil and Camphor while it was the lowestin Bankolmi leaf powder (53.28% and 48.27%) treated seed, followed by Castor

Table 2. Effect of different botanicals on larval and pupal development ofCallosobruchus maculatus in green gram

Treatments Larval Larval development Pupal Pupal developmentDevelopment reduction over development reduction over

(%) control (%) (%) control (%)Neem oil 0 d 100.00 0 d 100.00Castor oil 0 d 100.00 0 d 100.00Camphor 0 d 100.00 0 d 100.00Neem leaf powder 30 c 65.11 32 c 63.21Castor leaf powder 35 b 59.30 37 b 57.47Bankolmi leaf powder 40 b 53.28 45 b 48.27Untreated Control 86 a - 87 a -

Values are means of three replications. Means followed by same letter in a column are notsignificantly different (P>0.05) from each other by DMRT

leaf powder (59.30% and 57.47%) and Neem leaf powder (65.11% and 63.21%).The results thus revealed that Neem oil, Castor oil and Camphor were much moreeffective than Neem, Castor and Bankolmi leaf powder in reducing larval and pupaldevelopment. This result was almost similar to the finding of Haque et al. (2002).They evaluated different plant oils against C. maculatus on green gram and foundthat the percentage of larval and pupal development as well as adult emergence wasgreatly reduced by the application of plant oils on the seeds. Effects of botanicals on grain damage and grain content loss: The rate of graindamage and grain content loss by C. maculatus, were highest (81% and 26%) inuntreated control, followed by Bankolmi leaf powder (55.67% and 13.50%),Castor leaf powder (49.67% and 11.89%) and Neem leaf powder (35.67% and8.33%) treated green gram, respectively; while no damaged seeds and graincontent loss were found in Camphor, Castor oil and Neem oil treated seeds (Table3). The highest percentage reduction of damaged seeds and grain content lossreduction over control were found in Neem oil, Castor oil and Camphor (100%and 100%) treated seeds, respectively, while it was the lowest in Bankolmi leafpowder treated seeds (31.27% and 48.07%) followed by Castor leaf powder(38.67% and 54.26%) and Neem leaf powder (55.96 and 67.96%), respectively.


17

Table 3. Effect of different botanicals on per cent grain damage and grain contentloss of green gram by Callosobruchus maculatus

Treatments Grain damage Grain damage Grain content Grain content loss (%) reduction over loss (%) reduction over

control (%) control (%) Neem oil 0.00 d 100.00 0.00 d 100.00Castor oil 0.00 d 100.00 0.00 d 100.00Camphor 0.00 d 100.00 0.00 d 100.00Neem leaf powder 35.67 c 55.96 8.33 c 67.96Castor leaf powder 49.67 b 38.67 11.89 b 54.26Bankolmi leaf powder 55.67 b 31.27 13.50 b 48.07Untreated Control 81.00 a - 26.00 a -

Values are mean of three replications. Means followed by the same letter in column are notsignificantly different (P>0.05) from each other by DMRT

The performance of botanicals against pulse beetle as observed in the presentstudy was in agreement with the findings of Shaaya et al. (1997). They found thatleaf powder or oil extracts of plants suppress adult emergence and also reducedseed damage rate when mixed with stored grains.From these findings it was revealed that Camphor @ 2 gm/kg seeds, Neem oil @8 ml/kg seeds and Castor oil @ 8 ml/kg treated seeds performed best in consideringthe percent reduction of egg deposition, egg hatching, larval and pupaldevelopment, damaged seed and grain content loss applied against C. maculatusinfesting Barisal local variety of green gram. The effectiveness of the treatmentswas found in the following order: Camphor > Neem oil) > Castor oil > Neem leafpowder > Castor leaf powder > Bankolmi leaf powder > Untreated control. Thevariation in the effect of botanicals on pulse beetle as observed in the present studywas similar to the findings of Dhakshinamoorthy & Selvanarayanan (2002). Theyevaluated the effects of different natural products on the survival of C. maculatusinfesting stored green gram (Vigna radiata) and the results revealed that themortality of the beetle at 7 days after applying treatment was the highest (100%) inCastor oil, followed by Neem leaf powder (91.66%). In a study, Veer-Singh &Yadav (2003) reported that seed coating with Neem and castor oil gave significantprotection against pulse beetle compared to the untreated control in green gram. Effect of botanicals on seed germination: Germination tests were done at initialand 50 days after release (about two life cycles) of insects to evaluate the seedviability. Per cent germination of fresh seeds ranged from 90 to 91.80%, whileafter 50 days of treatment, the highest per cent germination ranged from 90 to90.50% in Camphor (90.50%) treated seeds, followed by Neem (90%) and Castoroil (90%). On the other hand, the lowest per cent germination was recorded inuntreated control (7.33%). Per cent germination ranged from 12 to 16.33 in othertreatments (Fig. 1)From the findings it was revealed that there were no significant effects ofCamphor, Neem oil and Castor oil in reducing the viability of green gram seeds.More or less similar works had been done by Ahmed et al. (2006) and theyreported that Camphor did not reduce the viability of green gram seeds whenapplied against C. chinensis and the viability retained (87.82 - 88.73%germination) up to 270 days after application of the camphor. Besides, Haque etal., (2002) also found that there was no adverse effect on the viability of seedstreated with plant oils.


18

REFERENCESAHMED M.S., KABIR K.H., NAHAR G., MIAH M.R.U. & RAHMAN M. A.

2006. Use of different containers, chemicals and indigenous materials for themanagement of pulse beetles (Callosobruchus chinensis L.) in storage.Bangladesh J.Ent.16 (2): 11-22.

ALI, M. R. & RAHMAN, M. M. 2006. Screening of different pulses as host forresistance against Callosobruchus maculatus Fab. J. Subtrop. Agric. Res.Dev. 4(1), 83-89

BEGUM, A., DEBNATH, S. K. & SEAL, D. R.1984. Studies on the food,temperature and humidity on the fecundity and development ofCallosobruchus analis Fab. (Coleoptera: Bruchidae), Bangladesh J. Zool.12(2), 71-78.

CHOWDURY, A. R. 1961. Pulse beetle. Agriculture Research Achievement in E.Pakistan (1960-1961). Directorate of Agriculture, East Pakistan, Dacca. pp.106-107.

DHAKSHINAMOORTHY,G. & SELVANARAYANAN, V. 2002. Evaluation ofcertain natural products against pulse beetle, Callosobruchus maculatus(Fab.) infesting stored green gram. Insect Environ. 8(1), 29-30.


19

0

20

40

60

80

100

% g

erm

inat

ion

Neem oil Castor oil Camphor Neem leafpow der

Castor leafpow der

Bankolmi leafpow der

UntreatedControl

Botanicals

Initial germination Germination after expt.

Fig. 1. Comparative germination percentages of green gram with different botanicalsbetween initial and after 50 days of treatment

FISHWICK, F. B. 1988. Pesticide residues in grain arising from post harvesttreatments. Aspects Appl. Biol. 17, 37-46.

GUJAR, G. T. & YADAV, T. D. 1978. Feeding of Callosobruchus maculatus Fab.(Coleoptera: Bruchidae) reared on different food and temperatures, J. storedprod. Res. 22(2), 71-75.

HAQUE, M. T., ISLAM, M. Z. & HUSAIN, M. 2002. Comparative study ofdifferent plant oils in controlling the pulse beetle in mungbean. :Entomology Division, BINA, Mymensingh, Bangladesh. Bangladesh. J.Training Develop. 15 (1&2), 201-205.

KEITA, S. M., VINCENT, C., SCHMIT, J. P., ARNASON, J. T. & BELANGER,A. 2001. Efficacy of essential oil of Ocimum basilicum L. and O.gratissimum L. applied as an insecticidal fumigant and powder to controlCallosobruchus maculatus (Fab.) (Coleoptera: Bruchidae). J. Stored Prod.Res. 37(4), 339-349.

RAHMAN, M. M., MANNAN, M. A. & ISLAM, M. A.. 1981. Pest survey ofmajor summer and winter pulse in Bangladesh. In proceeding of theNational Workshop on pulse, held during August 18-19, 1981. BangladeshAgric. Res. Ins., Joydebpur, Dhaka. pp. 265-273.

SAXENA, S. C. & YADAV, R.S. 1983. A new plant extract to suppress thepopulation build-up of Tribolium castaneum. In proceedings of the ThirdInternational Working Conference on stored product Entomology,Manhattan Kansas, USA. pp. 209-212.

SHAAYA, E., KOSTJUKOVSKI, M., EILBERG, J. & SUKPRAKARN, C. 1997.Plant oils as fumigants and contact insecticides for the control of stored-product insects. J. Stored Prod. Res. 33(1), 7-15.

VEER-SINGH & YADAV, D. S. 2003. Efficacy of different oils against pulsebeetle, Callosobruchus chinensis in greengram, Vigna radiata and theireffect on germination. Indian J. Ent. 65(2), 281-286.

YADAV, D. S., PANWAR, K. S. & SINGH, V. K. 1994. Management of pulsecrops in sequencial cropping. Indian Abst. Proc. Intercropping. Symposiumon pulse Research. 2-6 April, 1994, New Delhi, India. 27pp.

YUSOF, O. & HO, S. H. 1992. A survey of insecticidal resistance in Sitophiluszeamais Motsch. in Malaysia and Singapore. J. Plant Protec. in the Tropics.9, 219-225.

(MS received for publication 20 November 2012)


20

*Corresponding Author: Email: [email protected]

21

PREFERENCE BETWEEN DIMILIN-TREATED AND UNTREATEDFOOD MEDIA BY TRIBOLIUM CASTANEUM (HERBST) LARVAE

NUZHAT ARA, MOSHARROF HOSSAIN & *SELINA PARWEENDepartment of Zoology, University of Rajshahi, Rajshahi 6205, Bangladesh

ABSTRACTTribolium castaneum larvae of 9, 12 and 15 days old were released in the centreof a choice chamber, one half of which contained untreated flour and the otherhalf loaded with 0.25, 0.5, 1.0, 2.0 and 4.0 mg/g Dimilin-treated flour. The larvaldistribution in the treated and untreated food was recorded after 24, 48, 72, 96and 120 hrs of exposure. The doses 0.5 and 1.0 mg/g of Dimilin repelled thelarvae of all ages at all exposure periods. Treated flour with 2.0 and 4.0 mg/gshowed no effect on the distribution of 9 days old larvae, whereas, 12 and 15days old larvae showed attraction to 2.0 mg/g dose at longer exposure. Overallresults revealed that Dimilin at low doses can be used as larval repellent in grainand cereal stores to control T. castaneum.Keywords: Dimilin, larval distribution, T. castaneum.

INTRODUCTIONOne of the strategies of insect pest management in the grain storage and

groceries is to protect the environment and the biota from the chemical residuesof pesticides and to minimize the development of resistant strains of the pestinsects. Among these strategies, the Third Generation Insecticides (Williams,1956), which are known as Insect Growth Regulators (IGRs), proved to bepromising candidates against the field and storage insect pests of the grains andtheir products (Mian et al. 1985, Mondal & Parween 2000).

Dimilin, an IGR, belongs to a modern class of insecticides, the benzoyl phenylureas (BPUs) having a mode of action which is different from the conventionalneurotoxic insecticides (Hajjar 1985). The active ingredients (a.i.) of Dimilin areDiflubenzuron, which inhibits chitin synthesis in metamorphosing insect larvae ofDiptera, Lepidoptera and Coleoptera, thus disrupting moulting (Fox 1990).Hence, the compound has a very narrow window for acting against the insectlarvae, and is effective through contact or ingestion (Fox 1990, Ferdous 2006,Parween 1996, Mondal & Parween 2000). The treated larvae are either unable to


escape the old cuticle, or the new and weak cuticle of the next instar is lethallyinjured and the larvae die before reaching the next growth stage (Grosscurt 1978,Parween 1998).

The published literature examined mostly the insecticidal efficacy of Dimilin,or its effect on reproduction in the treated insects (Mondal & Parween, 2000).However, the compound whether acts either as an attractant or a repellent againstthe stored product insects have not been explored. So, the present work wasdesigned to observe the activity of Dimilin as either an attractant or a repellentagainst the larvae of different ages of the stored product insect pest, Triboliumcastaneum (Herbst) at different exposure periods.

MATERIALS AND METHODSTest Insect: Red flour beetle, Tribolium castaneum (Herbst) was chosen for

this experiment because the organism being an external feeder of cereals andgrains, and its different stages could easily be observed and collected easily.Moreover, it has a short life cycle at laboratory conditions (25-30 days at 27-30°Cand RH 70%).

About 100 adults of T. castaneum were collected from a stock culture rearedon whole wheat flour and yeast (standard food) in the Entomology Laboratory ofthe Department of Zoology, Rajshahi University. These adults were released onstandard food in glass container. After 24 hours, freshly laid eggs of the beetlewere collected using a 250µm mesh sieve (Khan & Selman 1981), and the eggswere placed in clean petri dishes with whole wheat flour at room temperaturewithout any light or humidity control. Eggs hatched into first instar larvae after 3-4 days. The larvae were allowed to feed on the same food. Food was replacedevery third day to avoid conditioning by the presence of larvae (Mondal 1984).From the subculture of larvae, known ages (9-, 12- and 15 day old) were selectedfor this experiment.

Source and doses of Dimilin: Dimilin® containing diflubenzuron (25% wp),an IGR marketed by M/S Northern minerals Ltd. India was used. The doses were0.25, 0.5, 1, 2 and 4 mg of Dimilin/g of flour.

Exposure periods: The larvae were exposed to the treated food for 24, 48, 72,96 and 120 hours for each dose.

Choice chamber: Choice chambers as described by Mathlein (1967), Mondal(1984) and Parween (1996) was used for this experiment. The choice chamber was

NUZHAT ARA, MOSHARROF HOSSAIN & SELINA PARWEEN

22

made of Petri dish with 9 cm diameter. A straight line was drawn at the middle ofthe Petri dish. One half of the Petri dish was loaded with dimilin-treated flour, andthe other half loaded with untreated flour.

Experimentation: Twenty larvae of a definite age were released along themidline of the choice chamber providing an option for the insects to show tropismtowards the treated or untreated food. The experiments were set separately for eachage group of larvae, dose and exposure period at room temperature. After everyexposure period, the treated and untreated portions of food were carefully pouredon separate pieces of paper subsequently sieved by a 500µm mesh sieve to get thelarval count from both types of food. Few larvae escaped during the longerexposure periods and those larvae were counted with the number of larvae thatwere present in the untreated food. The experiment was replicated thrice. Thepercentage distribution of the larvae in food was calculated from the averagenumber of the larvae recorded from three replications at each half of the choicechamber. Chi-square test was used to measure the differences of distribution ofinsects on either food court.

The experiment was conducted in 2011, from March to May.

RESULTS AND DISCUSSIONDistribution of 9 days old larvae: The data showed that 9 days old larvae

avoided Dimilin-treated food during all the exposure periods. The young larvaeavoided the food treated with 1.0 mg/g throughout all the exposure periods. Thenext dose which repelled the larvae was 0.5 mg/g during 24-, 48 and 96 hrsexposure. At all exposure periods, 2 and 4 mg/g treated flour showed no effect onthe larval distribution in the treated and untreated food, except 4 mg/g treated foodwas avoided (p<0.05) by the larvae during 120 hrs of exposure (Table 1).

Distribution of 12 days old larvae: In case of 12 days old larvae somepreference to the treated flour was noticed especially at the lowest dose (2 mg/g)from 48 to120 hrs of exposure. However, in 24, 96 and 120hrs exposure the larvaeshowed avoidance to food treated with 1.0 mg/g, whereas, significantly highernumber of larvae showed avoidance to the 0.5 mg/g treated flour throughout all theexposure periods (Table 2).

Preference to Dimilin-treated food by T. castaneum larvae

23

Table 1. Distribution of 9 days old larvae of T. castaneum in Dimilin-treated flourat different exposure times (N=60)

Exposure No. (%) Distribution of larvae in treated media (mg/g)time (h) χ2- values 0.25 0.5 1.0 2.0 4.0

24 No. (%) 23(38.33) 21(35) 5(8.33) 26(43.33) 27 (45)χ2-values 1.63 (NS) 2.7(p<0.05) 20.83 (p<0.001) 0.53 (NS) 0.3 (NS)

48 No. (%) 34(56.67) 20(33.33) 15(25.00) 31 (51.67) 27 (45)χ2- values 0.53 (NS) 3.53(p<0.05) 7.5(p<0.001) 0.03 (NS) 0.3 (NS)

72 No. (%) 31(51.67) 24 (40) 17(28.33) 28(46.67) 25 (41.67)χ2- values 0.03 (NS) 1.2 (NS) 5.63(p<0.001) 0.13(NS) 0.17(NS)

96 No. (%) 25(41.67) 21(35) 14(23.33) 27 (45) 29 (48.33)χ2- values 0.83 (NS) 0.53(NS) 8.53(p<0.001) 0.3 (NS) 0.03(NS)

120 No. (%) 30 (50) 26(43.33) 22 (36.67) 33(55) 21(35)χ2- values 0.0 0.53(NS) 2.13(p<0.05) 0.3(NS) 2.7(p<0.05)

Table 2. Distribution of 12 days old larvae of T. castaneum in Dimilin-treated flourat different exposure times (N=60)


24 No. (%) 34(56.67) 14(23.33) 10(16.67) 34(56.67) 24(40)χ2- values 0.13 (NS) 8.53(p<0.001) 13.33(p<0.001) 0.13 (NS) 1.2 (NS)

48 No. (%) 40(66.67) 12(20) 23(38.33) 39(65) 31(51.67)χ2- values 3.33 (p<0.05) 10.8(p<0.001) 1.63 (NS) 2.7(p<0.05) 0.03 (NS)

72 No. (%) 40.(66.67) 22(36.67) 24(40) 36(60) 29(48.33)χ2- values 3.33(p<0.05) 2.13(p<0.05) 1.2 (NS) 1.2 (NS) 0.03 (NS)

96 No. (%) 44(83.33) 16(16.67) 14(23.33) 46(76.67) 29(48.33)χ2- values 6.53(p<0.001) 6.53(p<0.001) 8.53(p<0.001) 8.53(p<0.001) 0.03 (NS)

120 No. (%) 50(83.33) 22(36.67) 15(25) 45(75) 29(48.33)χ2- values 13.33(p<0.001) 2.13 (NS) 7.5(p<0.001) 7.5(p<0.001) 0.03 (NS)

Distribution of 15 days old larvae: Mature larvae (15 days old) behaveddifferently from the immature ones towards the Dimilin-treated food. They


24

showed preference towards the treated flour at 2 mg/g during all the exposureperiods, but significantly avoided the treated food at doses from 1-4 mg/g at longerexposures (72 to 120 hrs). Again, these larvae preferred 2.0 mg/g treated flour at24 and 48 hrs exposures (Table 3).

Table 3. Distribution of 15-day old larvae of T. castaneum in Dimilin-treated flourat different exposure times (N=60)


24 No. (%) 51(85) 29(48.33) 22(36.67) 39(65) 27(45)χ2- values 14.7(p<0.001) 0.03 (NS) 2.13(p<0.05) 2.7(p<0.05) 0.3 (NS)

48 No. (%) 47(78.33) 25(41.67) 31(51.67) 44(71.67) 23(38.33)χ2- values 9.63(p<0.001) 0.8 (NS) 0.03 (NS) 6.53(p<0.01) 1.63 (NS)

72 No. (%) 40(66.67) 22(36.67) 7(11.67) 12(20) 7(11.67)χ2- values 3.33(p<0.05) 2.13(p<0.05) 17.63(p<0.001) 10.8(p<0.001) 17.63(p<0.001)

96 No. (%) 40(66.67) 21(35) 10(16.67) 13(21.67) 11(18.33)χ2- values 3.33(p<0.05) 2.7(p<0.05) 13.33(p<0.001) 9.63(p<0.05) 12.03(p<0.05)

120 No. (%) 47(78.33) 25(41.67) 10(16.67) 18(30) 25(25)χ2- values 9.63(p<0.001) 0.63 (NS) 13.33(p<0.001) 4.8(p<0.01) 7.5(p<0.001)

Results of the present experiment revealed that presence of Dimilin in the foodmore or less repelled the larvae of 9-15 days old when exposed for 24 to 120 hrs, butthe doses 1.0 and 0.5 mg/g were the most effective ones. The larval avoidancetowards Dimilin-treated food differed according to their age and exposure periods. Amixed behavior of the larvae was observed among the young larvae (9 days old), theyavoided the doses 1.0 and 0.5 mg/g throughout all the exposure periods, but showedno difference among the untreated and treated food with higher doses (2 and 4 mg/g)especially at longer exposure (120 hrs). Again, the 12 days old larvae showedpreference to 2 mg/g at 48 and 120 hrs exposures, though avoided the doses 1.0 and0.5 mg/g at all exposure periods. The mature larvae (15 days old) preferred the dose2 mg/g at 24 and 48 hrs exposures, but avoided these doses at longer exposures. Thelowest dose (0.25 mg/g) did not affect the larval distribution between the treated anduntreated food irrespective of their age and exposure periods.


25


26

Very few published reports are available on the choice for IGR-treated food bythe external feeders of the stored grain and cereal insects. Parween (1996) reportedthat Triflumuron (a chitin synthesis inhibitor) at doses of 0.01 and 0.05 mg/g didnot significantly repell 12 and 15 days old larvae of susceptible (FSS II) andresistant (CTC 12) strains of T. castaneum in 24 hrs exposure, but avoided(p<0.001) the dose 0.1 mg/g. The 9 days old larvae were equally distributed intriflumuron-treated and untreated foods. The reasons for the differences in resultsof the present work and that of Parween (1996) are that the compounds aredifferent though their mode of action is similar, short exposure period and lowdoses used. Moreover, it had been reported that Triflumuron was less palatable tothe larval T. castaneum (Parween 1998). Mazid et al. (2004) also observed thatTriflumuron repelled the larvae of Tribolium confusum.

Another IGR compound, Cyromazine acted as a repellent against the larvae ofboth species of Tribolium (Kamaruzzaman et al. 2009).

CONCLUSIONConsidering the above statement of Fox (1990) and from the present findings itcan be said that Dimilin at low doses was found to be avoided by T. castaneumlarvae irrespective of their age during exposures from 24 to 120 hours. So, it canbe used in the grain and cereal stores as surface treatment. This IGR shows verylow mammalian toxicity, and is non-toxic to fish, wildlife and domestic animals,and also easily degraded in soil and water.

REFERENCESFERDOUS, J. 2006 Effect of the predator, Xylocoris flavipes (Reuter) and the

insect growth regulators triflumuron and diflubenzuron on Triboliumcastaneum (Herbst). PhD Thesis. Institute of Biological Sciences, RajshahiUniversity.

FOX, D. 1990. Insect Growth Regulators. PJB Publ. Ltd. Richmond, UK.102 pp.GROSSCURT, A.C. 1978. Diflubenzuron: Some aspects of its ovicidal and

larvicidal mode of action and an evaluation of its practical possibilities.Pestic. Sci. 9:373-386

HAJJAR, N.P. 1985. Chitin Systhesis inhibitors as insecticides pp 275-310. In :Insecticides (Hutson D H & Roberts T R eds) 5 : Wiley. New York.

KAMARUZZAMAN, A.H.M., MONDAL, K.A.M.S.H. & PARWEEN, S. 2009.Distribution of larvae and adults of Tribolium castaneum (Herbst) andTribolium confusum DuVal in cyromazine treated food medium. Bangladeshj. entomol. 19(1):91-96.

KHAN, A.R. & SELMAN, B.J. 1981. Some techniques for minimizing thedifficulties in egg counting in Tribolium castaneum (Herbst). EntomolRecord J. Variat. 3:36-37

MATHLEIN, R. 1967. Repllents tested against stored-product beetle pests. Contr.Nat. Inst. Plant Prot., Stokholm, 13:112-447.

MAZID, M. A., MONDAL, K.A.M.S.H., PARWEEN, S. & ISLAM, W. 2004.Observation on preference between triflumuron treated and untreated foodmedia by Tribolium confusum (Duval). Bangladesh J. Zool., 32(2):141-146.

MIAN, L.S., MULLA, M.S. & HUSSAIN, N. 1985. Insect Growth Regulators ascontrol agents against stored product insects. J. Agric. 6(3):287-298.

MONDAL, K.A.M.S.H. 1984. Repellent effect of pirimiphosmethyl to Triboliumcastaneum Herbst. Int. Pest Control. 26(4): 98-99

MONDAL, K.A.M.S.H. & PARWEEN, S. 2000. Insect Growth Regulators andtheir potential in the management of stored product insect pests. IntegratedPest Management Reviews 5:255-295.

PARWEEN, S. 1996. Distribution and food consumption of larvae and adults ofTribolium castaneum Herbst on Baycidal treated medium. J. Bio-Sci., 4:113-119.

PARWEEN, S. 1998. Symptoms of Triflumuron intoxication in larvae ofTribolium castaneum (Herbst) (Coleoptera:Tenebrionidae). TriboliumInformation Bulletin, 38:268-270.

WILLIAMS, C.M. 1956. The juvenile hormones of insects. Nature (London)178:212-213.

(MS received for publication 02 December 2012)


27

29

OVIPOSITION AND FEEDING PREFERENCE OF HELICOVERPAARMIGERA (HUBNER) ON VEGETABLES

A. K. M. Z. RAHMAN1, M. A. HAQUE2 & S. N. ALAM1

1Entomology Division, Bangladesh Agricultural Research Institute, Gazipur-1701; 2Department of Entomology, Bangladesh Agricultural University,

Mymensingh

ABSTRACTStudies on host preference of Helicoverpa armigera (Hubner) were carried outat IPM lab of Entomology Division, Bangladesh Agricultural Research Institute(BARI), Gazipur, Bangladesh from October 2007 to August 2008. Fivevegetables, viz., tomato, pea, country bean, French bean and brinjal wereevaluated for oviposition and feeding preference of H. armigera underlaboratory condition. The highest number of eggs (25.32) were laid on floweringFrench bean plants, followed by flowering tomato plants (21.43), country bean(16.45) and flowering pea plants (9.38), while brinjal flowering plants receivedno egg whatsoever. In feeding preference test, significantly the highest numberof fruiting bodies were damaged in French bean (13.25), followed by countrybean (9.50), pea (7.75) and tomato (4.00). No brinjal fruit was damaged byH. armigera.

Keywords: Helicoverpa armigera, oviposition, feeding preference, vegetables.

INTRODUCTIONMore than 100 types of vegetables of indigenous and exotic origin are grown

in Bangladesh. Vegetable cultivation in Bangladeh covered an area of 4,51645 hain 2010-11 and produced 30,68000 t of vegetables (BBS 2011).

The yield per unit area is quite low since the insect pests cause 30 - 40% lossesin general and even 100% if no control measure is applied. A conservativeestimate puts about annual yield loss in vegetables at 25% due to insect pestsalone (Rahman 2006). Among the worst enemies, tomato fruitworm Helicoverpa(Heliothis) armigera occupies a prominent position in the world. It is apolyphagous pest occurring on a variety of crops (Mehrvar 2009, Chari et al.1990). The four chief characteristics polyphagy, high mobility, high fecundity, andfacultative diapauses of H. armigera help in attaining the status of a major pest(Fitt, 1989).


In general, Helicoverpa species preferentially feed on buds, flowers and fruits.The preference of fruiting structures and the tendency to move from one fruit toanother, often without consuming it, completely results in extensive damage tocrops even when the number of larger larvae are relatively low (Zalucki et al.1986). Larvae also feed on the leaves, especially in early instars. Damaged flowersand young fruit may fall off. Damaged fruits have roughly spherical holes madeby full grown larvae through which they escape for pupation in soil. Older fruitsrot or become deformed.

In Bangladesh H. armigera is becoming an alarming pest in different vegetablecrops. Infestation of H. armigera on tomato ranged from 17.38 to 20.98% atGazipur, Bangladesh (Anon. 2006). During 2006-07 seasons this infestation rateincreased up to 46.85% in Jessore and 21.05% in Hathazari and Chittagong (Anon.2007).

Helicoverpa armigera has a wide host range which includes cereals, pulses, oilseeds, fodder crops and horticultural crops. It is a major pest of tomato, cotton,pigeon pea, chickpea, sorghum and cowpea. Other hosts include dianthus, rosa,pelargonium, chrysanthemum, groundnut, okra, peas, field beans, soybeans,lucerne, Phaseolus spp., other Leguminosae, tobacco, potatoes, maize, flax, anumber of fruits (Prunus, Citrus), forest trees and a range of vegetable crops (CAB2006, Multani & Sohi 2002, Gahukar 2002 and Kakimoto et al. 2003).

Host species for H. armigera come from a broad spectrum of families andinclude important agricultural crops such as cotton, maize, chickpea, pigeonpea,sorghum, sunflower, soyabean and groundnuts (Fitt 1989). Females lay eggs onthe flowering and fruiting structures of these crops, where voracious larval feedingleads to substantial economic loss (Reed & Pawar 1982). The ability of ovipositingfemales to locate and utilize a wide range of hosts from a number of families isone of the major factors contributing to the pest status of this moth (Zalucki et al.1986, Fitt 1989). Considering the above facts, the present study was undertaken toobserve the oviposition and feeding preference of H. armigera on five selectedvegetables by free choice test.

MATERIALS AND METHODSTested vegetables: Five vegetables viz. country bean (Phaseolus vulgaris L.), pea(Pisum sativum L.), French bean (Phaseolus vulgaris L.), tomato (Solanumlycopersicum L.) and brinjal (Solanum melongena L.) were evaluated to observe

A.K.M. Z. RAHMAN, M.A. HAQUE & S.N. ALAM

30

the oviposition and feeding preference of H. armigera under laboratory condition.Pot culture of vegetables: Earthen pots of 35 cm diameter were used to provideroom for soil, roots and ensure good drainage and enough sun light. Beforeplanting, the pots were filled with mixture of soil, organic fertilizer and compost@ 1:1:1 ratio. Tomato, pea, country bean, French bean and brinjal seedlings weregrown separately from seeds in 300 pots and placed in a glasshouse maintained at28 ± 2.5ºC and 75 ± 5% RH. Regular watering was done for proper growth anddevelopment of the plant. Each plant was tightened with a split bamboo stick toavoid lodging. Different dates of planting were used to ensure continuous supplyof flowering plants of all species at the time of the tests. Experimental procedure for oviposition preference test: The ovipositionpreference of H. armigera was studied in the IPM lab of Entomology Division,Bangladesh Agricultural Research Institute (BARI), Gazipur, Bangladesh fromOctober 2007 to August 2008 in a free choice test. Two flowering plants in a potof each of the five vegetables, viz., tomato, pea, country bean, French bean andbrinjal were positioned randomly relative to each other within a Perspex cage withwooden frames (2.5 x 1.5 x 2 m3). Plant positions were rotated daily to eliminateany positional effect. The cage was placed in a glasshouse and the plants were keptwell apart from each other and potted plants were placed on different base heightto keep their crowns at the same height in the cage to minimize any effects of plantheight on oviposition. On the third day after emergence, the female moths werepaired with a newly emerged male in a mating cage. On the fourth day one pairwas released into the test cage at 5:00 pm. The following morning the eggs laid oneach plant were counted and a new set of plants was provided with a new pair ofmoths until 20 pairs had been tested on 20 sets of plants. Because of the inherentvariability in egg production among females, the proportion of eggs laid on eachplant by each female moth was calculated relative to all eggs laid on all plants byeach individual female. The eggs laid on the walls of the cage (<5% of all eggs)were not included in total egg laid. The experiment was laid out in completelyrandomized design (CRD) with three replicationsExperimental procedure for feeding preference test: The feeding preference ofH. armigera was also studied in the IPM lab of Entomology Division, BangladeshAgricultural Research Institute (BARI), Gazipur, Bangladesh from October 2007to August 2008 in a free choice test. For this, twigs of selected vegetablescontaining fresh fruiting bodies (young fruits) were cut from the plant and their cut

Oviposition and feeding preference of Helicoverpa armigera Hub.

31

ends were wrapped in wet cotton. Each twig having at least three fruiting bodieswas used. These fruits from five vegetables were kept together on a plastic tray(34cm x 22 cm x 4.5 cm) and kept in rearing case (61 cm X 61 cm X 76.5 cm).Now,10 fifth instar larvae were released at the center of the tray within the cage.Fresh twigs containing young fruits of 5 vegetables were offered to the larvae dailyfor three days. The number of fruits in different fruiting bodies damaged by thelarva after 24, 48 and 72 hours of initial release were counted. The feedingpreference of the larva was determined on the basis of number of fruits damagedin tested vegetables. The higher number of fruits damaged by the larva signified agreater preference by H. armigera.Data analysis: Data recorded on masses of eggs laid on five different vegetablesfor oviposition test and the numbers of fruiting bodies of these vegetablesdamaged in feeding preference test were analyzed using ANOVA. Leastsignificant difference (LSD) was used for mean separation at P>0.05. Raw datawere checked for homogeneity of variance and were transferred by logarimetrictransformation.

RESULTSHost preference of Helicoverpa armigera (Hubner) for different vegetables:Five common vegetables viz., tomato, country bean, pea, French bean and brinjalwere tested for host preference of H. armigera. Host preference was measuredbased on oviposition preference and feeding preference on different vegetables. Oviposition preference in a cage choice test: Helicoverpa armigera respondedsignificantly for its oviposition on different vegetables. Total number of eggsoviposited ranged from 0 to 455. It was observed that the highest number of eggs(455) were oviposited on French bean flowering plants, followed by tomato (364),country bean (263), and pea (150). There were no eggs laid on brinjal floweringplants (Table 1).There were significant differences among the host plant species in terms of meannumber of eggs laid per day by H. armigera (Table 1). The highest number of eggs(25.32) was laid on flowering French bean plant which was statistically similar tothose of tomato flowering plants (21.43). On the other hand, country bean and peaflowering plants received 16.45 and 9.38 eggs, respectively which were statisticallydifferent from each other. There was no egg laid on brinjal flowering plants.


32

Table 1. Number of H. armigera eggs laid on five flowering host plants in a cagechoice test using single mated female (n=20)

Host plants Number of Total number of Mean number of eggsovipositing eggs oviposited laid per female per day

females (Mean ± SE)Tomato 17 364 21.43±1.24 a

(1.20 )Country bean 16 263 16.45±1.08 b

(0.99)Pea 16 150 9.38±0.80 c

(0.85)French bean 18 455 25.32±1.35 a

(1.28)Brinjal 0 0 0.00 ±0.00 d

(0)LSD value at alpha 0.05 0.09965 CV% 6.60

Means within column followed by the same letter are not significantly different from one another(Least Significant Difference Test). Figure within parentheses are the transformed values based onLog transformation.

Feeding preference: Feeding preference of fifth instar larvae of H. armigera wasobserved at 24h, 48h and 72h after release. It was found that H. armigera preferreddifferent host differently. Twenty four hours after release, significantly the highestnumbers (7.25) of French bean pod were damaged by Helicoverpa larvae, followedby country bean (3.75), pea (3.00) and tomato (0.75). No fruiting bodies of brinjalwere found to be damaged by Helicoverpa larvae at 24 hours after release. Sametrends were found at 48 hour after release and significantly the highest number(13.00) of French bean pod were damaged by Helicoverpa larvae followed bycountry bean (9.00), pea (8.75) with no significant difference between them butsignificantly differed from that of tomato (3.75). At 72 hours after release, it wasobserved that significantly highest number of French bean pods (20.00) weredamaged by larvae, followed by country bean (15.00), pea (12.75) and tomato(8.50) which were significantly different from each other. No fruiting bodies ofbrinjal were found to be damaged during the whole study period (Table 2).


33


34

Total number of damaged fruits ranged from 0 to 40. The highest number of fruitsdamaged were found in French bean (40), followed by country bean (28), pea (24),and tomato (12). No brinjal fruits were damaged by larvae (Table 2).Among the different vegetables, the fifth instar larva did not prefer to feed on fruitsof brinjal and no damage was observed during the whole study period. The nextleast preferred vegetable was tomato where only 4.0 fruits were found to bedamaged which was significantly different from the remaining vegetables.Significantly, the highest number of damaged fruiting bodies of French bean(13.25) was found followed by country bean (9.5) and pea (7.75) and latter twowere statistically similar.

Table 2. Number of fruiting bodies of different vegetables damaged by H.armigera larvae in the laboratory during 2007-2008 seasons at Gazipur,Bangladesh

Host plants Fruiting bodies damaged by Total no. of Mean no. of fruitingH. armigera released after fruiting bodies bodies damaged

damaged (Mean ± SE)24 h 48 h 72 h

Tomato 0.75 c 3.75 c 8.50 d 12 4.0±1.17 c(1.09) (2.05) (3.00) (5.96)

Country bean 3.75 b 9.00 b 15.00 b 28 9.50 ±1.71 b (2.06) (3.08) (3.93) (7.91)

Pea 3.00 b 8.75 b 12.75 c 24 7.75 ±1.49 b(1.86) (3.04) (3.64) (7.34)

French bean 7.25 a 13.00 a 20.00 a 40 13.25±2.14 a(2.78) (3.68) (4.52) (9.28)

Brinjal 0.00 d 0.00 d 0.00 e 0 0.00 ± 0.00 d(0.71) (0.71) (0.71) (0.71)

LSD value at alpha 0.05 0.286 0.2654 0.2567 1.139CV (%) 14.35 9.41 8.27 11.85

Means within column followed by the same letter are not significantly different from one another(LSD Test, P >0.05). Figure within parentheses are the transformed values based on Squire RootTransformation

DISCUSSION

Oviposition preference: The result of the present study revealed that highernumber of eggs (25.32) were laid by H. armigera on flowering French bean plantswhich was statistically similar to that of flowering tomato plants (21.43). On theother hand, the number of eggs deposited on the country bean and flowering peaplants were 16.45 and 9.38, respectively which were statistically different fromeach other. While no egg was laid on flowering brinjal plants. Therefore, the orderof preference for oviposition of H. armigera was: French bean>tomato>countrybean>pea>brinjal. The reasons of this variation of oviposition preference of H.armigera might be due to genetical, morphological, antibiotic or antixenoticproperties of the plants. The results are in partial agreement with the findings ofJallow et al. (2001) who reported that Helicoverpa females showed strongoviposition preference for maize and okra, followed by tomato. There was adistinct non-preference for eggplant and pepper. Vijaya & Jayaraj (1981) alsostated that the order of oviposition preference of H. armigera was: pigeon pea >field bean > chickpea > tomato > cotton > chillies > mungbean > sorghum. Feeny(1993) reported that the various behavioral events leading to oviposition bylepidopterans are determined proximately by several interacting stimuli. Chemicalsignals play a prominent role but are by no means the most consistently importantat every stage. Proximate stimuli, whether chemical, physical or ecological,depend for their perception on the sensory modalities of adult females. Ovipositingfemales respond to these cues as indicators of host quality and this behavioralresponse may be influenced by associative learning that results in more efficienthost finding. Feeding preference: Among the different vegetables, the fifth instar larva of H.armigera did not prefer to feed on fruiting bodies of brinjal as no fruiting body wasfound to be damaged during the whole study period. The next least preferredvegetable was tomato which was significantly different from the remainingvegetables. Significantly, the highest number of fruiting bodies was found to bedamaged in French bean (13.25) followed by country bean (9.5) and pea (7.75).The result obtained from the present study is more or less in agreement with theobservation of Ahmad (2002). His studies revealed significant differences amongselected 15 test plants. The selected plants in order of preference on the basis ofconsumption were: Sorghum> Maize> Bermuda grass> Tomato> Cotton (NIAB-98) > Alfalfa> Rice >Castor oil> Okra> Cattail> (cotton (CIM-446) > Horse


35

purslane> Rape seed>Winter cherry> Calotrope. The order of the preference onthe basis of coefficient of utilization was Sorghum> Bermuda grass> Maize>Cotton (NIAB-98) > Tomato> Winter cherry> Castor oil> Alfalfa> Okra> Rice>Cotton (CIM-446) > Horse purslane> Calotrope > Rape seed> Cattail. None of theplants tested was found to be completely resistant to H. armigera. It was found that H. armigera did not prefer to feed on brinjal fruits in thelaboratory when other vegetables were available. Under field conditions, Kumar& Saini (2005) recorded quite a low population of this pest on arboreum genotypesin comparison to hirsutum ones, supporting the present findings. Less preferenceof brinjal fruits might be due to their inherent genetic characters andbiochemical composition (Singh 1988) which made them less suitable forlarval development as there was poor survival of H. armigera larvae onarboreum cotton genotype, LD-327, as compared to hirsutum genotypes(Singh et al. 1992). In the present studies, the lesser preference of brinjal fruitsby this pest than other vegetables may be due to differences in variousmorphological and biochemical attributes of brinjal.Kumar & Saini (2008) observed feeding preferences among different types offruiting bodies, irrespective of genotype/ hybrid, indicated a main preference ofthe third instar larva for flowers, followed by young cotton bolls and squares whenobserved after 24 hours of release. However, after 48 and 72 hours, the larvaexhibited an increasing tendency to attack young bolls. During the observationperiod, a larva damaged on average 8.00 flowers, 4.75 young bolls and 0.75 squareof cotton.Based on findings, flowering French bean plants were found to be the mostpreferred host for oviposition of Helicoverpa armigera (Hubner) among all theother tested plant species and flowering brinjal plants were not preferred at all. Thefifth instar larvae of H. armigera damaged highest number of French bean fruitingbodies but did not prefer to feed on brinjal fruiting bodies as no fruiting body wasfound damaged during the study period.

REFERENCESANON. 2006. Determination of the status of different borer pest complex of

country bean. Annual Report (2005-06). Division of Entomology,Bangladesh Agric. Res. Inst., Joydebpur, Gazipur, 86pp.


36

ANON. 2007. Performance trials of different exotic tomato lines against tolcv andwhitefly. Annual Report (2006-2007), Division of Entomology, BangladeshAgric. Res. Inst., Joydebpur, Gazipur, 163pp.

AHMAD, K.J. 2002. Factors affecting pest host interaction in IPM of Helicoverpaarmigera (Hübner) in Pakistan. Ph.D. Thesis., Dept. Entomol., Univ. Agric.,Faisalabad. Pakistan.

BBS 2011. Bangladesh Bureau of Statistics, Yearbook of Agricultural Statistics ofBangladesh. 23rd Edition, Planning Division, Ministry of Planning,Government of the People's Republic of Bangladesh. 329pp.

CAB INTERNATIONAL. 2006. Crop Protection Compendium. Wallingford, UK.CHARI, M.S., PRASAD, R. & ALI, S.M.A. 1990. Eco friendly pest management

of Helicoverpa armigera (Hubner) in Chick pea. In: Proceedings of Non-Pesticidal Management of Cotton and Pigeon pea pests, April 10-11,Hyderabad, pp. 54-56.

FEENY, P. 1993. Ecological opportunism and chemical constraints on the hostassociations of swallowtail butterflies. In: Scriber JM, Tsubaki Y,Lederhouse RC (Editors), Swallowtail butterflies: Their ecology andevolutionary biology. Scientific Publishers, Inc. Gainesville Fla. pp. 9-15.

FITT, G.P. 1989. The ecology of Heliothis species in relation to agro ecosystems.Annu. Rev. Ent. 34: 17-52.

GAHUKAR, R.T. 2002. Population dynamics of Helicoverpa armigera (Hubner)(Lepidoptera: Noctuidae) on rose flowers in central India. J. Ent. Res. 26:265-276.

JALLOW, M.F.A., MATSUMURA, M. & SUZUKI, Y. 2001. Ovipositionpreferences of Japanese Helicoverpa armigera (Hubner) (Lepidoptera:Noctuidae). Appl. Entomol. & Zool. 36: 419-426.

KAKIMOTO, T., FUJISAKI, K. & MIYATAKE, Z. 2003. Egg laying preference,larval dispersion, and cannibalism in Helicoverpa armigera (Lepidoptera:Noctuidae). Annals Entomol. Soc. America 96: 793-798.

KUMAR, S. & SAINI, R.K. 2005. Incidence of Bollworms in Promising Cultivarsof Cotton in Haryana. J. Cotton Res. & Development 19, 277- 280.


37

KUMAR, S. & SAINI, R. K. 2008. Feeding preference and damage potential ofHelicoverpa armigera (Hübner) on different promising CottonGenotypes/Hybrid. J. Agr. Sci. Tech. 10: 411-420

MEHRVAR, A. 2009. Persistence of different geographical isolates of Helicoverpaarmigera nucleopolyhedrovirus in two types of soils under differentconditions. J. Biol. Sci. 9: 264-267.

MULTANI, J.S. & SOHI, A.S. 2002. Helicoverpa armigera (Hubner) oncarnation, Dianthus caryophyllus Linn. in Punjab. Insect-Environ. 8: 82.

RAHMAN, M.M. 2006. Vegetable IPM in Bangladesh. In: Radcliffe EB,Hutchison WD (Editors), Radcliffe's IPM World Textbook, URL:http://www.ipmworld.umn.edu/chapters/rahman.htm, University ofMinnesota, St. Paul, MN, USA.

REED, W. & PAWAR, C.S. 1982: Heliothis: a global problem. In: Proceedings ofthe International Workshop on Heliothis Management. Pantanchera, India,ICRISAT. pp. 9-14.

SINGH, S.J., SANDHU, S.,& SINGLA, M.L. 1992. Ecology of Heliothisarmigera (Hub.) on chickpea in Punjab. J. Insect Sci. 3: 47-52.

SINGH, S.P. 1988. Fifteen years of AICRP on Biological Control. Tech. Bull.No.8, Project Directorate of Biological Control, Bangalore, 320 p.

VIJAYAKUMAR, A., & JAYARAJ, S. 1981. Studies on the food plant ecology ofHeliothis armigera (Hubner) (Lepidoptera, Noctuidae). Indian J. Agric. Sci.21: 375-379

ZALUCKI, M.P., DAGLISH, G., FIREMPONG, S. &, TWINE, P. 1986. Thebiology and ecology of Heliothis armigera (Hubner) and H. punctigeraWallengren (Lepidoptera : Noctuidae) in Australia : What do we know?Australian J. Zool. 34: 779-814.

(MS received for publication 04 January 2013)


38

39

DETERMINATION OF PYRETHROID AND ORGANOPHOSPHORUSINSECTICIDE RESIDUE IN BRINJAL SAMPLES COLLECTED FROM

SOME SELECTED REGIONS OF BANGLADESH

M. S. AHMED1, M. A. SARDAR2, M. AHMAD2 & K. H. KABIR1

1Entomology Division, Bangladesh Agricultural Research Institute (BARI), Gazipur; 2Department of Entomology, Bangladesh Agricultural University, Mymensingh.

ABSTRACTA study was carried out in the pesticide analytical laboratory, BangladeshAgricultural Research Institute, Gazipur during 2008-2009 seasons for thedetermination of residue level of Synthetic Pyrethroid (Cypermethrin) andOrganophosphorus (viz. Quinalphos, Diazinon, Malathion, Fenitrothion andAcephate) insecticides in environmental brinjal samples using suitable protocolsdeveloped for GC-FTD and GC-ECD. Out of the analyzed 75 collected samplesof brinjal from farmers field of Jessore, Gazipur and Rangpur, 38.67% werefound to be contaminated with the insecticides. Most of the samples containedCypermethrin, Acephate and Fenitrothion residues. Quinalphos, Acephate andFenitrothion were found as multiple residue products representing 10.35% of thetotal contaminated samples and the rest 89.65% contained single insecticideresidue. About 44.83% of the contaminated samples had residue above MRL(Maximum Residue Limit) irrespective of single or multiple residues. Malathionresidue was found only in one sample from Gazipur. Diazinon was detected infew samples from all of the locations. The detected residue levels of bothMalathion and Diazinon were below the MRL, which might be due to higherrate of degradation.

Keywords: Insecticide, residue, degradation, brinjal.

INTRODUCTIONBrinjal (egg plant) is widely cultivated in Bangladesh and grown in both

kitchen and commercial gardens during Rabi and Kharif seasons. Brinjal isattacked by 53 species of insect pests (Nayar et al. 1995), among which brinjalshoot and fruit borer is the most serious and destructive pest in Bangladesh (Alam& Sana 1964, Alam 1969). Farmers used a wide range of organophosphorus andsynthetic pyrethroid insecticides with various spray formulations advocated fromtime to time against sucking pests and brinjal shoot and fruit borer (Prakash 1988,Agnihotri et al. 1990). Besides several ongoing integrated pest management(IPM) programs at home and abroad, pest control still largely depends on the use


of chemical pesticides (Flint & Gouveia 2001). The usages of insecticides are themajor means for the control of insect pests of vegetables in the field than othermanagement options. The chemical means are vital and provide a rapid, cost-competitive and typically effective pest management tool (MacIntyre et al. 1989).As there is no other sustainable alternative method of controlling vegetable pests,the growers solely depend on insecticides when pests attack the vegetable plants.Most of the brinjal growers of Jessore, Rangpur and Gazipur regions inBangladesh use large quantities of chemical insecticides indiscriminately tocontrol these pests. At present, most of the farmers have been using "cocktail"(mixture of 3-5 insecticides) and spraying at a high frequency on brinjal (Kabir etal. 1996, Rashid et al. 2003). This practice not only increases cost of productionbut also causes environmental pollution and human health hazard (MacIntyre et al.1989, Forrester 1990), develop pest resistance (Ekesi 1999) and also destroynatural enemies (Alam et al. 2006). From survey conducted (Anon. 2001, Ahmedet al. 2005) at different regions of Bangladesh, it was found that farmers used 71different kinds of insecticides in vegetables at an alarming frequency an averageof 99 times in a cropping season on brinjal in Jessore, 26 times in Rangpur and 20times in Gazipur. It was also found that many farmers sprayed insecticides everyor every alternate day even twice a day (rainy season) on brinjal at Jessore, one totwo days interval in Gazipur and Rangpur. Most of the farmers sell vegetableswithout looking at withholding period of insecticidal spray. A considerable numberof farmers of those regions sell brinjal immediately after spray or at an interval of0-2 days after spray that cause pesticide residue load in vegetables. Sometimespersistent pesticides accumulate in the higher food chain of both wildlife andhuman and concentrate by biomagnifications (Senapati et al. 1992). An intensifieduse of insecticides can cause a serious public health hazard especially in the formof residues in food (Mansingh. et al. 1996). Obviously, insecticide residue data onbrinjal is important to the public in general because of potential hazard to health.With a realization of the danger to living organism and the environment thatinsecticides pose, the present study was designed to determine and document theinsecticide residue level in environmental brinjal samples.

MATERIALS AND METHODSThe study was conducted in the pesticide analytical laboratory, Bangladesh

Agricultural Research Institute, Joydebpur, Gazipur during 2008-2009 seasons.The details of materials and methods adopted are given below:

M. S. AHMED, M. A. SARDAR, M. AHMAD & K. H. KABIR

40

Chemicals used in insecticide analysis: In the analysis of the insecticides,different types of chemicals were used. Those were: Acetone, n-hexane,Cyclohexane, Methanol, Acetonitrile, Silica gel 60, Sodium sulphate andinsecticide standards. All the chemicals and standards for Synthetic Pyrethroid(cypermethrin) and Organophosphorus (viz. quinalphos, diazinon, malathion,fenitrothion and acephate) insecticide were obtained from Sigma-AldrichLaborchemikalien, Gmbh P. O. Box-100262, D-30918, Seelze, Germany viaBangladesh Scientific Pvt. Ltd. Dhaka, Bangladesh. Collection of brinjal samples from farmers field: A total of seventy five samplesof brinjal were collected from farmers field of three different locations such asJessore, Gazipur and Rangpur. In selecting fields, standing brinjal plants andedible brinjal at harvest were the main criteria and samples were collectedaccording to regulation made in the ''Guidelines for the control of pesticideresidues in foods" (Anon. 1996), which incorporate the EU directive (Anon.1979)and Codex recommendations (Anon.1993) regarding sampling. The size of thesample of brinjal was 1kg. Field collected samples were stored in "Chilled box"and carried to the laboratory at the quickest time. Extraction, separation and clean up of brinjal samples: Collected samples ( 250g)were ground thoroughly with the meat grinder (Handmixer M-122, Bamix,Switzerland) or chopped by knife and mixed well. A sub sample of 20g was takeninto a wide mouth jar, then 100ml of hexane was added to it. Sodium Sulphate(Na2SO4) was also added with sample until water was removed from the sample.The mixture was then macerated with high-speed homogenizer (Ultra-turrax, IKAT18 basic, Germany) for 2 minutes. The homogenized material was then poured into250 ml conical flask and placed into the shaker (Refrigerated Shaker, Rexmed,Sweden) for 12 hrs continuous shaking. The slurry was then filtered throughWhatman filter paper no.40 and a Buchner funnel with suction. The flask and filtercakes were rinsed with 25ml of hexane each. The filtrate was then transferred into250 ml round bottom flask and was dried to around 5-7 ml by evaporation using arotary vacuum evaporator (Laborota-4001, Heidolph, Germany). Then, theconcentrate filtrate was collected in a centrifuge tube adjusted at 10ml volume whichwas then centrifuged at 16500 rpm for 10 minutes with Laboratory RefrigeratedCentrifuges, Sigma-3K30, Germany. The supernatant was collected and cleaned upby Super Phase Extraction (SPE) cartridge. Then the final volume was kept in 10mlvolumetric flask. Before injection, this volume was again cleaned up by HighPerformance Liquid Chromatography (HPLC) filter which was ready for injection.

Determination of pyrethroid and organophosphorus insecticide residue in brinjal

41

Detection and quantification of insecticide residue in brinjal samples: Theconcentrated extracts were subjected to analysis by GC-2010 (Shimadzu). FlameThirmionic Detector (FTD) was used for the detection of Quinalphos, Diazinon,Malathion, Fenitrothion and Acephate and Electron Capture Detector (ECD) forCypermethrin. The capillary column used in FTD was ATTM-1, 30 m in length,0.25 mm inner diameter (ID) and 0.25 µm film thickness and in case of ECD itwas Optima-1 and length, ID and film thickness were the same. Nitrogen was usedas carrier and make up gas in ECD and in FTD it was Helium. The instrumentparameters for detecting organophosphorus insecticides and Cypermethrin were asfollows.Organophosphorus insecticidesMachine : GC-2010[Injection Port SPL]Injector (Auto) : AOC 20iInjection Mode : SplitTemperature : 250oCCarrier Gas : HeFlow Control Mode : Linear velocityLinear Velocity : 40.0 cm/secPurge Flow : 3.0 ml/minSplit Ratio : 30.0Injection Volume : 1.0 µl

[Column Oven]Column Oven Temperature Program:Initial Temperature : 150oCEquilibrium Time : 1.0 minTotal Program Time : 10.0 minRate (oC/min) Temperature (oC) Hold Time (min)

-- 150.0 1.0010.0 220.0 2.00[Column Information]Column Name : ATTM-1Column Length : 30.0 m


42

Film Thickness : 0.25 µmInner Diameter : 0.25 mm [Detector Channel 1 FTD]Temperature : 280oC Stop Time : 10.0 minCurrent : 1.0 pAMakeup Gas : HeMakeup Flow : 30.0 ml/minH2 Flow : 1.5 ml/minAir Flow : 145.0 ml/minCypermethrin Machine : GC-2010[Injection Port SPL]Injector (Auto) : AOC 20iInjection Mode : SplitFlow Control Mode : Linear velocityTemperature : 280oCPurge Flow : 3.0 ml/minSplit Ratio : 10.0Injection Volume : 1.0 µl[Column Oven]Column Oven Temperature Program:Initial Temperature : 160oCEquilibrium Time : 1.0 minTotal Program Time : 18.0 minRate (oC/min) Temperature (oC) Hold Time (min)-- 160 1.0010 270 6.0[Column Information]Column Name : Optima-1Column Length : 30.0 mInner Diameter : 0.25 mmFilm Thickness : 0.25 µm


43


44

[Detector Channel 1]Detector : ECDTemperature : 300oCStop time : 18.0 minCurrent : 1.0 pACarrier/Makeup Gas : N2Makeup flow : 30 ml/min

Prior to injection of the sample extract, standard solutions of differentconcentrations of five insecticides were prepared and injected with the aboveinstrument parameters. The samples were calibrated (retention time, peak areaetc.) against four pointed calibration curve of standard solution of concernedinsecticide. Each peak was characterized by its retention time. Sample results wereexpressed in ppm automatically by the GC software which represented theconcentration of the final volume injected. From this value the actual amount ofinsecticide residue present in the sample was determined by using the followingformula.Residue in sample (ppm)

Conc. obtained in injected volume (ppm) × Quantity of final volume (L)= ---------------------------------------------------------------------------------------------------------------------

Amount of sample taken (kg)

RESULTSDetection of insecticide residue in brinjal samples: Freshly collected brinjalsamples were analyzed to assess the residue level of Synthetic Pyrethroid(Cypermethrin) and Organophosphorus (viz. Quinalphos, Diazinon, Malathion,Fenitrothion and Acephate) insecticides. The samples were extracted, separated,cleaned-up and analyzed using validated single and multi residue analysis GC-2010 methods. Fig.1. shows the chromatograms of standards of someorganophosphorus insecticides. Results are presented in tabular form which wasmade on the chromatograms. One chromatogram of multi product residue obtainedfrom the environmental brinjal samples of each location are shown in Fig. 2-4. Inthis way the results of other samples were also made by in-built GC-2010software.

Fig. 1. Chromatograms of standards of some organophosphorus insecticides run by GC-FTD

Fig. 2. Chromatograms of multiple products (Acephate, Fenitrothion, Quinalphos) obtained fromthe extract of brinjal (EBrJ7) collected from Jessore

Fig. 3. Chromatograms of multiple products (Acephate, Quinalphos) obtained from the extract ofbrinjal (EBrG18) collected from Gazipur

Fig. 4. Chromatograms of multiple products (Fenitrothion, Quinalphos) obtained from the extractof brinjal (EBrR22) collected from Rangpur


45

Insecticides residue in brinjal collected from selected regions: Twenty five samplesof brinjal from each of the three locations (Gazipur, Jessore and Rangpur) wereanalyzed to find out the presence of the left over residue of six insecticides. There weretotal of 9 contaminated samples in Gazipur location in which single or multi insecticideresidue were detected (Table 1). Eight samples, each contaminated by singleinsecticide residue where one sample of Malathion and Diazinon had residue levelbelow MRL and one sample of Fenitrothion contained 0.331 ppm residue which wasabove MRL. Of 5 samples of Cypermethrin (frequency of 5), only one samplecontained residue level of 0.432 ppm which was above MRL and the remaining 4samples had the residue below MRL. Only two insecticides were found in a sample asreferred to multiple product residues. This multiple product sample containedQuinalphos and Acephate; Quinalphos had the residue level of 0.691 ppm and aboveMRL and Acephate, almost half in quantity of Quinalphos which was below MRL. Table 1. Quantity of residue of different insecticides estimated from brinjal in

GazipurLocation Samples Frequ Contaminated samples (no.) Detected Residue level MRL

analyzed encies Total Sample Sample insecticide(s) (mg kg-1) (mg kg-1)*(no.) of single of multi

product productGazipur 25 1 9 1 Fenitrothion 0.309 0.1

1 1 Quinalphos 0.691 0.21 Acephate 0.309 0.51 1 Malathion 0.104 0.51 1 Diazinon 0.290 0.55 5 Cypermethrin 0.094, 0.192, 0.2

0.432, 0.078,0.052

*FAO/WHO Codex Alimentarius Commission, Codex Committee on Pesticide Residues (1993).

In Jessore location there were eleven contaminated brinjal samples and out of these10 samples had single product residue and the remaining one had multiple productresidues (Table 2). Out of 10 single products contaminated sample, the residue ofCypermethrin occurred in 7 samples (frequency 7) in which 4 samples showedresidue level exceeding MRL ranging from 0.235-0.718 ppm and the remaining 3samples with little quantity of Cypermethrin. The quantity of Fenitrothion andAcephate detected in the contaminated single sample were much higher as 1.349


46

and 1.121 ppm than any other insecticides. The residue levels of these twoinsecticides were obviously above MRL. Only one sample was of multi productresidue of 3 insecticides such as Fenitrothion, Quinalphos and Acephate in whichFenitrothion and Quinalphos were above the MRL and Acephate below MRL.Diazinon was detected in a contaminated sample of brinjal, but its residue level wasbelow MRL. Malathion was not detected in the brinjal of Jessore location.

Table 2. Quantity of residue of different insecticides estimated from brinjal inJessore

Location Samples Frequ Contaminated samples (no.) Detected Residue level MRLanalyzed encies Total Sample Sample insecticide(s) (mg kg-1) (mg kg-1)*

(no.) of single of multiproduct product

Jessore 25 11 1 Fenitrothion 0.708 0.11 Quinalphos 0.967 0.2

Acephate 0.428 0.52 1 Fenitrothion 1.349 0.12 1 Acephate 1.121 0.50 Malathion 0.000 0.51 1 Diazinon 0.384 0.57 7 Cypermethrin 0.086, 0.104, 0.2

0.718, 0.294, 0.235, 0.462,

0.059


Nine brinjal samples were found to be contaminated out of 25 analyzed samplesin Rangpur (Table 3). There were 8 contaminated samples of single product inwhich 6 samples were of Cypermethrin (frequency 6). Only two samples showedresidue levels of 0.228 and 0.351 ppm Cypermethrin which were above MRL andrest of the 4 samples had little quantity of Cypermethrin. Two other contaminatedsamples with Acephate and Diazinon had residue level below MRL and Malathionwas not detected. Only two insecticides Fenitrothion and Quinalphos were foundin a sample as multiple product residues both of which were much above the MRL,Quinalphos being much more in this brinjal sample.


47

Table 3. Quantity of residue of different insecticides estimated from brinjal inRangpur

Location Samples Frequ Contaminated samples (no.) Detected Residue level MRLanalyzed encies Total Sample Sample insecticide(s) (mg kg-1) (mg kg-1)*

(no.) of single of multiproduct product

Rangpur 25 1 9 1 Fenitrothion 0.839 0.11 Quinalphos 1.221 0.21 1 Acephate 0.473 0.50 Malathion 0.000 0.51 1 Diazinon 0.408 0.56 6 Cypermethrin 0.185, 0.090, 0.2

0.077, 0.228,0.351, 0.057


DISCUSSIONThe analyzed 75 samples of brinjal collected from farmers' field of Jessore,Gazipur, and Rangpur showed that 38.67% samples were contaminated with sixinsecticides either singly or multiple product residues, in which 44.83% sampleshad residues above MRL. Most of the samples contained Cypermethrin, Acephateand Fenitrothion residue in brinjal. Multiple product residues were detected in alllocations. This indicated that farmers applied more than one insecticides on brinjalin Jessore, Gazipur and Rangpur regions. Malathion and Diazinon were detectedin isolated conditions but their residue levels were below MRL. Malathion wasdetected from brinjal only in Gazipur and Diazinon in all the three locations.Therefore, the residue levels of Fenitrothion, Quinalphos, Acephate andCypermethrin were more pronounced in brinjal grown in particular location ascompared to Diazinon and Malathion. In Jessore region, the contaminated sampleswith insecticides were higher than Gazipur and Rangpur irrespective of single ormultiple product residues. Most of the commercial farmers of vegetablesespecially in Jessore region have been spraying "cocktail" (mixture of 3-5insecticides) at every or every alternate day (Kabir et al. 1996, Rashid et al. 2003).This irrational and inappropriate use of insecticides in the vegetables might causethe multiple residues of insecticides even at or above MRL level. Virgina & Bajet


48

(1996) found residue of ogranophosphate insecticides (e.g. Methomyl, Triazophos,Methyl parathion and Diazinon) using rapid field kit from market basket samplesof eggplant, tomato, cabbage and Chinese peachy that exceeded MRL. The resultsof the present work agreed in some cases with the works of the above authorsalthough the methods of residue analysis were different. It could be assumed thatthe factors and conditions adopted for the analysis of insecticide residue in thepresent study were perhaps as precise as required to quantify low level of residue.

REFERENCESANON. 1979. Methods of Sampling for the Official Control of Pesticide Residues

in and on Fruits and Vegetables. July 24, European Commission Directive79/700/EEC.

ANON. 1993. Codex alimentarius, pesticide residues in food. Joint FAO/WHOStandards Program, FAO, Rome, Italy, 2: pp. 378-386.

ANON. 1996. Guidelines for the Control of Pesticide Residues in Foods. NationalFood Agency of Denmark (in Denish), 146pp.

ANON. 2001. Coordinated research on insecticide residue and resistance in majorvegetables grown in Bangladesh. Report on Contact Research Project,BARC, BARI, Joydebpur, Gazipur, 102 pp.

AGNIHOTRI, N. P., SINHA, S. N. & CHAKRABARTI, A. K. 1990. Bioefficacyof some synthetic pyrethroid insecticides against Leucinodes orbonalisGuen. and their residues on brinjal fruit. Indian J. Ent. 52(3): 373-378.

AHMED, M. S., SARDAR, M. A., HAQUE, M. A. & KABIR, K. H. 2005. Asurvey on the pattern of insecticidal usage for the protection of brinjal(Solanum melongena) from the attack of insect pests in Jessore. BangladeshJ. Zool. 33(1): 57-63.

ALAM, M. Z. 1969. Insect pests of vegetables and their control in East Pakistan.Agric. Inf. Serv. Dacca, 146 pp.

ALAM, M. Z. & SANA, D. L. 1964. Biology of the brinjal shoot and fruit borer,Leucinodes orbonalis Guenee in East Pakistan, pp. 192-200. In: Review ofResearch, Division of Entomology (1947-64). Agric. Inf. Serv. Dacca.


49

ALAM, S. N., HOSSAIN, M. I., ROUF, F. M. A., JHALA, R. C., PATEL, M. G.,RATH, L. K., SENGUPTA, A., BARAL, K., SHYLESHA, A. N.,SATPATHY, S., SHIVALINGASWAMY, T. M., CORK, A. & TALEKAR,N. S. 2006. Implementation and promotion of an IPM strategy for control ofeggplant fruit and shoot borer in South Asia. AVRDC Tech. Bull. 36: 4-11.

BASHA. A. A., CHELLIAH, S. & GOPALAN, M. 1982. Effect of syntheticpyrethroids in the control of brinjal fruit borer (Leucinodes orbonalisGuen.). Pesticides, 16(9): 10-11.

EKESI, S. 1999. Insecticide resistance in field populations of the legume podborer, Maruca vitrata Fabricius (Lepidoptera: Pyralidae), on cowpea, Vignaunguiculata (L.), Walp in Nigeria. International J. Pest Management, 45(1):57-59.

FLINT, M. L. & GOUVEIA, P. 2001. IPM in practice: Principles and methods ofintegrated pest management. University of California, Agriculture andNatural Resources Communication Services, 6701 San Pablo Avenue,Oakland, California, USA, 196 pp.

FORRESTER, N. W. 1990. Designing, implementing and servicing andinsecticide resistance management strategy. Pesticide Sci. 28: 167-180.

KABIR, K. H., BAKSH, M. E., ROUF, F. M. A., KARIM, M. A. & AHMED, A.1996. Insecticide usage pattern on vegetable at farmer level of Jessore regionin Bangladesh: A Survey Finding. Bangladesh J. Agril. Res. 20(2): 241-254.

MACINTYRE, A. N., ALLISON, N. & PENMAN, D. R. 1989. Pesticides: Issuesand options for New Zealand. Ministry of the Environment, Wellington,New Zealand, 7: 29.

MANSINGH, A., ROBINSON, D. E., WALKER, N. & THOMAS, C. 1996.Distribution, fate and effects of pesticides in tropical marine environment,Presented at the third IAEA-MEL Res. Coordination meeting heredia, CostaRica, 9-13 September.

NAYAR, K. K., ANANTHAKRISHNAN, T. N. & DAVID, B. V. 1995. Generaland Applied Entomology. Eleventh ed. Tata McGraw-Hill Publ. Co. Ltd.New Delhi-110002, 557 pp.


50

PRAKASH, O. 1988. Schedule of insecticidal application against insect pestcomplex of brinjal with special reference to brinjal shoot and fruit borer,Leucinodes orbonalis Guen. Indian J. Ent. 50(1): 16-19.

RASHID, M. A., ALAM, S. N., ROUF, F. M. A. & TALEKER, N. S. 2003. Socio-economic parameters of eggplant pest control in Jessore district ofBangladesh. AVRDC Tech. Bull. 29: 1-54.

SENAPATI, H. K., SAHOO, B. K., PATTNAIK, M. R. & PAL, A. K. 1992.Persistence of some common pesticides in pigeon pea. Orissa J. Agril. Res.5(1-2): 100-103.

VIRGINA, R. O. & BAJET, C. M. 1996. Pesticides in the Philippine environment,pp. 61-77. In: DIZON, T. D., EUSEBIO, J. E., DUENAS, J. N., PALIS, F.V. & MABBAYAD, M. O. (eds.). Proceedings. Anniversary and AnnualScientific Meeting Pest Management Council of the Philippine, Davao City.



51

*Corresponding Author: [email protected]

53

EFFECT OF DIAPAUSE ON SURVIVAL AND REPRODUCTIVEPERFORMANCE OF BUMBLEBEE (BOMBUS TERRESTRIS) QUEENS

YONG JUNG KWON1, MD RUHUL AMIN2* & KYI KYI THAN1

1School of Applied Biosciences, Kyungpook National University, Daegu, Korea;2Department of Entomology, Bangabandhu Sheikh Mujibur Rahman

Agricultural University, Gazipur, Bangladesh

ABSTRACTIn the present study bumblebee (Bombus terrestris) queens were managed todiapause at 0°C and 5°C for 2, 3 and 4 months and investigations were done toknow their mortality, colony initiation and foundation, and offspring production.Queens diapaused at 5°C for 2 months showed lower percentage of mortalityduring diapause (3.9%), activation (4.8%), colony initiation (11.9%), and colonyfoundation (14.6 %) but needed longer time for oviposition. However, diapauselength and temperature did not affect colony foundation period, but the queensdiapaused at 5°C for 3 months produced significantly higher number of firstbrood egg cells, first brood workers, worker population in the colony, sexualmales and gynes, thus the conditions indicating better performances forcommercial breeding.Keywords: Bumblebee queens, colony, diapause, foundress queen, oviposition.

INTRODUCTIONBumblebees, Bombus terrestris L. (Hymenoptera: Apidae) are being used for

pollination of 25 crop species in more than 30 countries of the world (Gosterit &Gurel 2005). Their demand for crop pollination in the temperate zone is alsoincreasing because they are active forager at low temperatures, cloudy and windyweather conditions. Of 239 known bumblebee species, B. terrestris is the mostwidely used pollinator as its colony population is larger than others (Gosterit &Gurel 2005, Beekman et al. 2000). Bombus terrestris colonies are beingcommercially produced under controlled conditions and a total of 900,000colonies are sold per year in the world (Gosterit et al. 2009).

In the temperate region, bumblebee colonies produce sexual males and gynes(queens) in the summer. The gynes entered into diapause after they had mated, and


the colony with the foundress queen and males die in late summer. The gynesemerge from diapause after a period of six to nine months whenever environmentaltemperature rises (Alford 1969). Therefore, the gynes forage in day light about oneweek to activate them for colony initiation. The gynes initiate colonies by laying abatch of diploid (fertilized) eggs that produce only workers which are responsiblefor nursing the foundress queen and subsequent broods (Goulson et al. 2002, Jandtet al. 2009, Couvillon & Dornhaus 2010). A colony becomes feasible for croppollination whenever it is populated with 60 -70 workers, and within or after aperiod of two months, new sexuals (males and gynes) emerge in the colonies whichdistorts pollination activity (Gosterit & Gurel 2007).

Key factors affecting commercial rearing of B. terrestris are diapause of thefoundress queens, availability of food sources, worker population in the colony,timing of the emergence and number of sexuals and colony lifetime (Beekman &van Stratum 2000, Lopez-Vaamonde et al. 2009, Amin et al. 2011). Among thesefactors, diapause of the foundress queen is the main obstacle in artificial breeding(Velthuis & Doorn 2006). To overcome this problem, breeders usually storedqueens at low temperature for two to five months (Amin et al. 2007). However,diapause length affects body mass, survival and reproduction of queens (Amin etal. 2007, Yoon et al. 2010).

Beekman et al. (1998) studied the effect of diapause length and temperature ondiapause survival and post-diapause performance of B. terrestris and reported thatoptimum diapause condition could result in lower number of gyne mortality andbetter performance for colony initiation. In addition, Beakman & Van Stratum(2000) reported that colony characteristics, such as number of workers in the firstand second brood, total workers, sexual males and gynes in the colonies are relatedto diapause experience of the queens. Information regarding the effects of diapauselength on survival of B. terrestris queens during diapause, activation, colonyinitiation, colony foundation, and also on colony productivity are scanty.Therefore, in this study, mated bumblebee queens were allowed to diapause at 0°C and 5°C for 2, 3 and 4 months in order to find out their convenient diapausecondition for survival, and secondly, the surviving queens were nested to evaluatetheir reproductive performance.

YONG JUNG KWON, MD RUHUL AMIN & KYI KYI THAN

54

MATERIALS AND METHODSOrigin and mass culture of insect: Experimental insects were the 7th generationqueens obtained from B. terrestris colonies that were imported from Koppert B.V., The Netherlands in the year 2006. The colonies were reared in a growthchamber in the laboratory of the Department of Applied Biosciences, KyungpookNational University, Daegu, Korea. The growth chamber was maintained at astandardized temperature of 28±1°C (Duchateau & Marien 1995), 60±2% RH, andthe bees were fed with ad libitum frozen pollen grain of the Korean Kiwi, Actinidiaarguta Planch, and sugar solutions (1.5: 1 w/v). Seven day old gynes having bodymass 700-800 mg were allowed to mate with 9 day old males (Amin et al. 2007).Then 10 to 12 inseminated queens were kept in each transparent plastic box (16 ×11 × 7 cm) provided with pollen and sugar solution (1.5:1 w/v) to rear the queensin a growth chamber for two weeks with a view to adopt physiological diapause.Diapause conditions: In each plastic container (20 × 14 × 10 cm) 30-35 matedqueens were kept together. Prior to keeping queens, the containers were filled upto 50 % of its height with peat soil. The containers were covered with hermetic lidattached with a layer of blotting paper for preventing water condensation.Containers with B. terrestris queens were then kept in different refrigerators for aperiod of 2, 3 and 4 months, and the temperature was maintained at 0°C and 5°C.For each temperature and diapause length, four boxes of queens were kept. Aftera period of 2, 3 and 4 months of diapause the boxes of the queens were taken outand mortality percentage of the queens in each diapause treatment was recorded. Activation: On completion of diapause treatments surviving queens wereintroduced into flight cages (40 × 40 × 60 cm) having illumination facility. Allqueens of a same diapause treatment were kept in a cage. The cages were providedwith ad libitum pollen grain and sugar solutions (1.5: 1 w/v). The cages withqueens were kept for one week in a growth chamber maintained at 28±1°C, 60±2%RH and 12:12 light: dark condition. The light was provided with 220/240Vfluorescent white light (Philips MX204HF136, 40 Hz, λ = 0.96-0.17) at anintensity of ~ 700 lux on the floor of the flight cages. The intensity of light wasmeasured with a digital lux meter and the photophase was regulated with timer.The cages were monitored daily and dead queens in the cages were removed. Afterone week, percent queen mortality of each diapause treatment was calculated. Colony development: For each treatment, a total of 35 activated queens wereallowed for oviposition in small transparent plastic boxes (16 cm × 11 cm ×7 cm).

Effect of diapause on bumblebee queens

55

In each box, one queen was kept with frozen pollen grain in a 4 cm diameter Petridish and sugar solution (1.5:1, w/v) in a perforated plastic tube (0.35 cm3). Oneanesthetized B. terrestris worker and 1-2 day-old frozen queen pupa were addedto each rearing box to stimulate the queens for oviposition as described byDuchateau & Marien 1995. Each pupa was horizontally fixed with paraffin on harddrawing paper, so that the pupa could not roll and the queen could sit foroviposition (Kwon et al. 2003). Pollen grains were supplied daily into the rearingboxes and sugar tube was changed weekly. The frozen pupa and anesthetizedworker were substituted once a week unless the queen laid eggs on the cocoon oron the hard drawing paper. If a queen did not lay eggs within 4 weeks she wasdiscarded from calculation. When the queen laid eggs, the narcotized worker wasremoved from that rearing box. The boxes were kept in these conditions until theworkers of the first brood cells emerged. Data were recorded to determine thecolony initiation period (number of days between the day after first pupa supplyuntil the laying of first eggs), number of first brood egg cups, colony foundationperiod (number of days between the day after first egg laying until the emergenceof first brood cell workers), number of first brood workers, and queen mortalityrate during colony initiation and foundation periods. For further development, thecolonies were shifted to larger colony boxes (27 cm × 18 cm × 13 cm) that wereconnected to sugar tanks (30 cm × 20 cm × 4 cm) by a cotton filter. Newlyemerged sexuals were harvested daily and total number of workers, males andgynes in each colony were recorded. Data analysis: Data of the queen mortality were analyzed by ?2 test and one wayanalysis of variance was employed for analyzing the colony initiation and colonyfoundation period, number of first brood egg cells and workers, total workers andsexuals. Data were expressed as mean ± se and the means were separated byDMRT. All the analyses were performed using IBM SPSS statistics 19.

RESULTSMortality percentages of foundress queens in diapause conditions are

presented in Table 1. Results indicated that queen mortality during diapausesranged from 3.9 to 16.5% and the results showed significant difference (χ2 = 11.2).The queen mortality percentage during activation showed significant difference(χ2 = 27.2) and the mortality was 4.8 to 32.2%. There was significant differenceamong the queen mortality data during colony initiation (χ2 = 39.7), and theobserved mortality was 11.9 to 50.0%. The queen mortality percentages during


56

colony foundation also showed significant difference (χ2 = 31.0) and mortalityvaried from 14.6 to 53.8%. The results in Table 1 indicated that the queensdiapaused at 5°C for 2 months showed the highest survival rate during diapauses,activation, colony initiation, and colony foundation. Table 1. Effect of diapause length and temperature on the mortality rate (%) of B.

terrestris queens

Diapause length Total Mortality rate (%) duringand temperature queen Diapause Activation Colony initiation Colony foundation2 m 0oC 128 10.9 14.9 28.8 31.93 m 0oC 133 16.5 25.2 31.3 33.34 m 0oC 134 14.2 32.2 50.0 53.82 m 5oC 128 3.9 4.8 11.9 14.63 m 5oC 133 6.0 8.8 12.3 20.04 m 5oC 133 10.5 16.8 21.2 25.6

χ2 values for diapauses = 11.2, activation = 27.2, colony initiation = 39.7 and colony foundation =31.0 with df = 5, p > 0.05

Diapause treatments showed significant effect (F5, 185 = 6.5, p < 0.001) oncolony initiation periods (Fig. 1). Colony initiation periods ranged from 5.2 ± 2.7to 10.8 ± 6.8 days and the queens experiencing diapause for 3 or 4 months initiatedcolonies significantly earlier than those diapaused for 2 months.


57

Fig. 1. Effect of diapause length and temperature on the colony initiation period of B. terrestris.Data expressed as mean ± SE (n). Bars with no common letter are significantly different(DMRT, p < 0.05).


58

There was significant effect of the diapause length and temperature on theproduction of first brood egg cells (F5, 176 = 5.2, p < 0.001; Fig. 2). The queenswhich experienced diapause for 3 months at 5°C produced significantly highernumber of egg cells (4.4±1.4). Fig. 3 showed that the colony foundation periods(development time of the first brood workers) with regard to diapause duration andtemperature varied from 23.3±3.3 to 24.6±2.0 days, but there was no significantdifference (F5, 141 = 1.9, p > 0.05).

Fig. 2. Effect of diapause length and temperature on the production of first brood egg cells of B.terrestris. Data expressed as mean ± SE (n). Bars with no common letter are significantlydifferent (DMRT, p < 0.05).

Fig. 3. Effect of diapause length and temperature on the colony foundation period of B. terrestris.Data expressed as mean ± SE (n). Bars with no common letter are significantly different(DMRT, p < 0.05).

Production of first brood workers in relation to the diapause treatments of thefoundress queens are presented in Fig. 4 and the results showed significantdifference (F5,141 = 2.7, p < 0.05). The first brood egg cells produced a range of7.5±3.9 to10.2±4.2 workers, and the queens diapaused for 4 month at 5oCproduced the highest number of workers.

Table 2 showed the offspring production of B. terrestris queens in relation todiapause conditions. Diapause lengths and temperatures revealed significant effect(F5, 81 = 2.6, p < 0.05) on the total number of worker production in the colonies.Total number of worker production varied from 180.6±12.6 to 228.8±11.6 percolony and the queens which diapaused 3 months at 5oC produced the highestnumber of workers.

The diapause conditions revealed significant effects on male (F5, 71 = 2.3, p <0.05) and gyne (F5, 58 = 5.3, p < 0.05) production. Number of male and gyneproduction varied from 192.2±10.4 to 239.6±11.9 and 84.5±6.1 to 116.1±4.4 percolony, respectively. These results indicated that the queens which diapaused for 3months at 5oC produced higher number of sexual males and gynes.


59

Fig. 4. Effect of diapause length and temperature on the production of first brood worker of B.terrestris. Data expressed as mean ± SE (n). Bars with no common letter are significantlydifferent (DMRT, p < 0.05).

Table 2. Effect of diapause length and temperature on the offspring production ofB. terrestris. Data expressed as mean ± SE (n). Means within a columnfollowed by common letter are not significantly different (DMRT, p <0.05)

Diapause length Number of offspringand temperature Worker Male Gyne2 m 0oC 182.1 ± 12.9 (14) b 192.2 ± 10.4 (13) c 86.7 ± 4.6 (10) c3 m 0oC 196.7 ± 12.4 (14) ab 214.8 ± 12.8 (14) ac 97.5 ± 5.3 (11) bc4 m 0oC 197.8 ± 11.7 (16) ab 201.6 ± 12.1 (11) bc 93.0 ± 6.5 (9) c2 m 5oC 180.6 ± 12.6 (12) b 206.0 ± 14.3 (12) ac 84.5 ± 6.1 (10) c3 m 5oC 228.8 ± 11.6 (16) a 239.6 ± 11.9 (14) a 116.1 ± 4.4 (12) a4 m 5oC 218.4 ± 11.2 (15) ab 231.5 ± 11.1 (13) ab 111.5 ± 6.9 (12) ab

DISCUSSIONOne of the key strategies for year-round rearing of B. terrestris is breaking or

shortening of diapause which is an essential physiological state of bumblebeequeens. Several authors have tried to induce hibernation of bumblebee queensunder controlled conditions to overcome this constraint (Tasei 1994, Beekman etal. 1998).

Beekman & Van Stratum (2000) reported that queen lifetime decreases withincreasing diapauses. The present study showed that the queens diapaused at 5oCfor 2 months had higher survival rate during diapauses, activation, colonyinitiation, and colony foundation compared to other treatments, which indicatedthat shorter diapause treatment is favorable for survival of bumblebee queens.

Bumblebee colonies reared under identical conditions differ in their timing ofthe switch from the ergonomic to reproductive phase (Müller et al. 1992, Beekmanet al. 1998). This study showed that the foundress queens experiening diapause for2 months needed longer time for colony initiation, whereas the queensexperiencing diapause for 3 months at 5oC produced higher number of first broodegg cells. On the contrary, queens experiencing diapause for 4 months at 5oCproduced higher number of first brood workers. Asada (2004) reported that B.hypocrite queens diapaused at 5oC for 4 months in a refrigerator were effective fornest initiation.


60

Beekmand & van Stratum (2000) reported that diapauses cause morphological,physiological and behavioral variations among bumblebee queens anddifferentiate their reproductive performances. The present study showed thatproduction of sexual males and gynes as well as total worker population in the B.terrestris colonies were related to diapause treatments. The foundress queensdiapaused for 3 months at 5°C exerted better reproductive performances as theyhad produced significantly higher number of sexual males, gynes and workerpopulations. Beekman & van Stratum (2000) found increasing trend of workerpopulation in B. terrestris colonies with increasing diapause length of the queens.They also reported that the queens diapaused for 4 months had produced thehighest number of worker. Amin et al. (2008) studied the effects of photoperiodsand diapause length on the colony productivity of B. terrestris and reported thatthe queens diapaused for 3 months produced higher number of sexual males andgynes.

Diapause acts on metabolic activity of insects, and affects respiration, ceasescell division and eventually interrupts life span (Denlinger 2002, Shingleton et al.2003). However, the metabolism rate is dependent on ambient temperature (Hodek& Hodková 1988). Ambient temperature affects the nervous system of insects andregulates the activities of the endocrine glands which may change in theirreproduction behavior and performances. Yoon et al. (2010) studied the effects ofchilling temperatures on the mortality and reproduction behavior of B. terrestrisqueens and reported that the queens experienced diapause at 2.5°C and 70% RHshowed highest survival rate, shortest preoviposition period, and consequentlyhigher number of worker population, and sexual males and gynes. This studyshowed that the queens diapaused for 3 months at 5oC had shortest preovipositionperiod. These queens also produced higher number of first brood egg cells as wellas first brood workers, sexual males, gynes, and worker population.

Diapause lengths influence the intensity of reproductive competition of B.terrestris queens with workers, and the worker population in the colony interruptsqueen reproductive physiology, aggression, and task performances which hadassociation with colony characteristics (Beekman & van Stratum 2000, Lopez-Vaamonde et al. 2009, Amin et al. 2007, Amin et al. 2008, Amin et al. 2011). Thepresent study showed that survival and colony performances of B. terrestrisqueens are related to diapause length. The findings of this study also indicated thatthe queens experiencing diapause for 2 months at 5oC had higher survival rate,


61

whereas the queens diapaused for 3 months at the same temperature exertedgreater capacity for colony development. Therefore, bumblebee breeders mayselect 3 months and 5oC as a suitable diapause condition for commercial rearingof B. terrestris, and researchers should give emphasis to mitigate diapause length.

REFERENCESALFORD, D.V. 1969. A study of the hibernation of bumblebees (Hymenoptera:

Bombidae) in southern England. J. Anim. Ecol. 38, 149-170.AMIN, M.R., KWON, Y.J. & SUH, S.J. 2007. Photoperiodic influence on the

body mass of bumblebee, Bombus terrestris and its copulation duration. J.Appl. Entomol. 131, 537-541.

AMIN, M.R., KWON, Y.J. & SUH, S.J. 2007. Effect of photoperiod andhibernation duration on the lifespan of Bombus terrestris. Entomol. Res. 37,89-94.

AMIN, M.R., KWON, Y.J. & SUH, S.J. 2007. Impact of artificial photoperiodismon the colony development of bumblebee Bombus terrestris. Entomol. Sci. 10,315-321.

AMIN, M.R., KWON, Y.J. & SUH, S.J. 2008. Reproductive responses tophotoperiod and temperature by artificially hibernated bumblebee Bombusterrestris queens. Entomol. Res. 38, 250-256.

AMIN, M.R., KWON, Y.J. & THET, Z.M. 2011. Effect of worker number anddiapause duration on the colony parameters of bumblebee, Bombus terrestris(Hymenoptera: Apidae). J. Asia-Pacific Entomol. 14, 455-458.

ASADA, S. 2004. Studies on year round rearing of Japanese native bumblebees(Bombus spp.) for buzz-foraging crop pollination. Bull. Kanagawa PrefectualAgril. Res. Inst. 144, 3-18.

BEEKMAN, M. & van STRATUM, P. 2000. Does the diapause experience ofbumblebee queens Bombus terrestris affect colony characteristics? Ecol.Entomol. 25, 1-6.

BEEKMAN, M., van STRATUM, P. & LINGEMAN, R. 1998. Diapause survivaland post diapause performance in bumblebee queens (Bombus terrestris). Ent.Exp. Appl. 89, 207-214.

BEEKMAN, M., van STRATUM, P. & LINGEMAN, R. 2000. Artificial rearing


62

of bumblebees (Bombus terrestris) selects against heavy queens. J. Apic. Res.39, 61-65.

COUVILLON, M.J. & DORNHAUS, A. 2010. Small worker bumblebees(Bombus impatiens) are hardier against starvation than their larger sisters.Insectes soc. 57, 193-197.

DENLINGER, D.L. 2002. Regulation of diapause. Annu. Rev. Entomol. 47, 93-122.

DUCHATEAU, M.J. & MARIEN, J. 1995. Sexual biology of haploid and diploidmales in the bumblebee, Bombus terrestris. Insectes. soc. 42, 255-266.

GOSTERIT, A. & GUREL, F. 2005. Comparison of developmental patterns ofimported and native Bombus terrestris L. (Hymenoptera: Apidae) colonies inthe Mediterranean coastal region. Turk. J. Vet. Anim. Sci. 29, 393-398.

GOSTERIT, A. & GUREL, F. 2007. Effects of weight of queens after diapauseson colony development in the bumblebee, Bombus terrestris L. Akdeniz Univ.Ziraat Fakultesi Dergisi. 20, 67-70.

GOSTERIT, A., GALIC, A. & GUREL, F. 2009. The effect of queen removal onsexual production in the bumblebee, Bombus terrestris L. (Hymenoptera:Apidae). Turk. J. Zool. 33, 403.407.

GOULSON, D., PEAT, J., STOUT, J.C., TUCKER, J., DARVILL, B.,DERWENT, L.C. & HUGHES, W.H.O. 2002. Can alloethism in workers of thebumblebee, Bombus terrestris, be explained in terms of foraging efficiency?Anim. Behav. 64, 123-130.

HODEK, I. & HODKOVÁ, M. 1988. Multiple role of temperature during insectdiapause: a review. Ent. Exp. Appl. 49, 153-165.

JANDT, J.M., E. HUANG & DORNHAUS, A. 2009. Week specialization ofworkers inside a bumblebee (Bombus terrestris) nest. Behav. Ecol. Sociobiol.63, 1829-1836.

KWON, Y.J., SAEED, S. & DUCHATEAU, M.J. 2003. Stimulation of colonyinitiation and colony development in Bombus terrestris by adding a malepupa: the influence of age and orientation. Apidologie. 34, 429-437.

LOPEZ-VAAMONDE, C., RAINE, N.E., KONING, J.W., BROWN, R.M.,PEREBOOM, J.J.M., INGS, T.C., RAMOS-RODRIGUEZ, O., JORDAN,W.C. & BOURKE, A.F.G. 2009. Lifetime reproductive success and longevity


63

of queens in an annual social insect. J. Evol. Biol. 22, 983-996.MÜLLER, C.B., SHYKOFF, J.A. & SUTCLIFFE, G.H. 1992. Life history

patterns and opportunities for queen-worker conflict in bumblebees(Hymenoptera: Apidae). Oikos. 65, 242-248.

SHINGLETON, A.W., SISK, G. & STERN, D.L. 2003. Diapause in the pea aphid(Acyrthosiphon pisum) is a slowing but not a cessation of development. BMCDev. Biol. 3, 1-12.

TASEI, J.N. 1994. Effect of different narcosis procedures on initiating ovipositionof prediapausing Bombus terrestris queens. Ent. Exp. Appl. 72, 273-279.

VELTHUIS, H.H.W. & DOORN, N.A.V. 2006. A century of advances inbumblebee domestication and the economic and environmental aspects of itscommercialization for pollination. Apidologie. 37, 421-451.

YOON, H.J., LEE, K.Y., HWANG, J.S. & PARK, I.G. 2010. Chilling temperatureand humidity to break diapauses of the bumblebee queen Bombus terrestris.Intl. J. Indust. Entomol. 20, 93-98.

(MS Received for publication 10 January 2013)


64

65

BIOCHEMICAL ATTRIBUTES OF DIFFERENT SUGARCANEVARIETIES AND THEIR IMPACT ON STEM BORER INFESTATION

M. A. RAHMAN1, M. Z. ALAM2, M.R.U. MIAH2, M. I. H. MIAN3 & M. M. HOSSAIN4

1Bangladesh Sugarcane Research Institute, Ishurdi, Pabna, Bangladesh;2Department of Entomology, 3Department of Plant Pathology, 4Department ofHorticulture, Bangabandhu Sheikh Mujibur Rahman Agricultural University,

Gazipur 1706, Bangladesh

ABSTRACTA study was undertaken to determine the biochemical constituents viz.,chlorophyll 'a', chlorophyll 'b', chlorophyll 'total', total N, P, K, Ca, Mg and Nain ten different sugarcane varieties (Isd31, Isd32, Isd33 Isd 34, Isd 35, Isd 36,Isd 37, Isd 38, Isd 39 and Isd 40) and their impact on stem borer (Chilotumidicostalis Hampson) infestation. The result showed that the variety Isd32possessed significantly higher level of chlorophyll 'a', chlorophyll 'b',chlorophyll 'total' as well as higher level of stem borer infestation (9.58%) incomparison to other varieties. On the contrary, significantly higher level of totalN, P, Ca, Mg, Na, total sugar, pol of cane as well as stem borer infestation(11.60%) was found in the variety Isd34. This variety also contained lower levelof reducing sugar and K. The relationship between stem borer infestations andall biochemical attributes except K showed positive correlation, which indicatedthe biochemical constituents in the variety interrupted stem borer attack.Considering the biochemical attributes and stem borer infestations, the findingsof the study suggested that the variety Isd34 is rich in nutrient content comparedto other varieties, but should not be recommended for cultivation where stemborer is a major pest.

Kewords: Sugarcane, stem borer, biochemical attributes, impact.


INTRODUCTION

Sugarcane (Saccharum officinarum L.) is one of the major food-cum-industrialcash crops in Bangladesh. It is the main source of sucrose and is used for sugar andalcohol production. Around 70% of world's sugar production is based onsugarcane (Chowdhury & Vasil 1993). Sugarcane is a C4 plant with a high rate ofphotosynthesis (its rate lies around 150-200% above the average of other plants).

Plant leaves change chemically with age and the quantity of amino-nitrogenpresent in the phloem sap changes with the progress of growth and maturation ofleaves, shoot and stem (Raupp & Denno 1993). Plants provide water and nutrientsto phytophagous insects and ensure availability of nitrogen in the form of aminoacids and proteins that affect the growth rate of immature insects and its deficiencyaffects the insect population on plants (Horn 1988). Moisture stressed plantsappear to suffer from insect attacks, since a given amount of feeding brought aboutgreater injury to plants. Plant contains various chemicals, which may act asstimulant or repellent for egg laying and feeding. The present study wasundertaken to determine the relative effects of biochemical constituents ofsugarcane such as chlorophyll (a, b & total), total N, P, K, Na, Mg and Ca and totalsugar, reducing sugar and fiber in different varieties and their effect on the attackof the stem borer (Chilo tumidicostalis Hampson, Family: Crambidae, Order:Lepidoptera).

MATERIALS AND METHODSExperimental site, duration, design and layout: The study was carried out in theexperimental farm of Bangladesh Sugarcane Research Institute (BSRI), Ishurdi,Pabna during the cropping season of 2011-2012. Ten BSRI released sugarcanevarieties viz., Isd 31, Isd 32, Isd 33, Isd 34, Isd 35, Isd 36, Isd 37, Isd 38, Isd 39and Isd 40 were selected for the study. The crop was grown following standardcultivation procedure as described by Rahman & Pal 2003. Recommended dosesof manure (cowdung @ 10 t ha-1) and fertilizers (Urea, TSP, MP, Gypsum andZnSO4 @ 326, 250, 180, 189 and 10 kg ha-1, respectively) were applied (BARC2005). The experiment was laid out following randomized complete block design(RCBD) with three replications. The unit plot size was 5m × 5m. Distance betweenunit plots was 1m and block to block distance was 2 m. Every unit plot was plantedwith 175 setts in 5 rows and each row was planted with 35 setts. Interculturaloperations such as irrigation, weeding, mulching, thinning and other operations

M.A. RAHMAN, M.Z. ALAM, M.R.U. MIAH, M.I.H. MIAN & M.M. HOSSAIN

66

were done properly throughout the cropping season for proper growth anddevelopment of the plants.Collection of data: Sugarcane plants were selected randomly from theexperimental field. Samples of deep green leaves were collected from upperportion (third/fourth/fifth leaf from the top) of the selected cane 120 days afterplanting (DAP). The leaf area was measured using a leaf area meter. Data on leafmorphology, chemical constituents and characters of all leaf samples wererecorded. Leaf morphology included colour, thickness and leaf moisture content.Chemical constituents included chlorophyll a, chlorophyll b and total chlorophyll,reducing sugar, total sugar, nutrient element contents and fiber content. Percentstem borer infestation was also recorded during June and July. Determination of chlorophyll content: Chlorophyll a, chlorophyll b and totalchlorophyll content of young leaves of different sugarcane varieties weredetermined following acetone method as described by Witham et al. (1986). Todetermine chlorophyll content, the leaf samples were collected from the thirdleaves, counted from top of the main stem at 180 DAP. Exactly 0.05g fresh leafwas turned into paste by blending and taken in a centrifugal tube with 4.0 ml(80%) acetone and centrifuged at 3000 rpm for 10 minutes. The volume wasincreased up to 20 ml with 80% acetone. The reading was taken at 645 and 663 nmin a UV spectrophotometer and expressed as mg/g fresh leaf weight (Arnon,1949). Determination of Sugar and nutrient content: Sugar contents (reducing andtotal) of leaf samples were determined following the method described bySomogyi (1952) using Bertrand-A, Bertrand-B and Bertrand-C solutions. Samplesof fresh leaves were collected from the top. The specimens of fresh leaf sampleswere cut into small pieces, air dried and ground for the determination of N content.According to Yamakawa (1992) first nitrogen was estimated by using MicroKjeldahl Method.Determination of pol of sugarcane: Pol percent in sugarcane leaf samples weredetermined following the method described by Chen (1985). The clear juice wasfilled in a 200 mm polarimeter tube. Any air bubbles insides the tube after fillingwith clarified juice were carefully avoided. The polarimeter/saccharimeter wasadjusted and focused distinctly as the position of the image was changed. The polwas corrected against Brix from the correction table.

Biochemical attributes of sugarcane varieties and stem borer infestation

67

Observation infestation of stem borer: Stem borer infestation generally startedfrom May and continued up to October. Data on the pest incidence were recordedin June and July. For efficiency study, percent infestation was computed bycounting total and infested canes for individual plot and the per cent infestationwas computed.Data analysis: Data were analyzed statistically for ANOVA (Steel & Torrie, 1960)using MSTAT-C computer software. Simple correlation of sugarcane stem borerinfestation with the chemical constituents of leaves were computed. The meanswere compared using Duncan's Multiple Range Test.

RESULTS AND DISCUSSION

Chlorophyll content: Chlorophyll 'a' content in leaf of ten sugarcane varietiesvaried from 0.81 to 2.60 mg/g fresh leaf weight (gfw). Significantly the highestchlorophyll 'a'content was recorded from variety Isd 32. Stem borer infestation inIsd 31 (1.75 mg/gfw) and Isd 37 (1.73 mg/gfw) was statistically similar butsignificantly higher compared to other 7 varieties. The lowest chlorophyll'a'content was found in variety Isd 35 (0.81 mg/gfw) followed by Isd 39 (0.83mg/gfw) and their difference was statistically similar. Chlorophyll 'a' in Isd 40(1.64 mg/gfw) was not statistically different from Isd 33 (1.60 mg/gfw) and Isd 34(1.59 mg/gfw) (Table 1).

Chlorophyll 'b' in fresh leaves of ten sugarcane varieties ranged from 0.18-0.79mg/g fresh weight. Significantly the highest value was found in Isd 32 followed byIsd 40 (0.62 mg/g) and Isd 37 (0.58 mg/g). Significantly the lowest quantity ofchlorophyll 'b' content was recorded from leaves of Isd 35, which was followed byIsd 39, Isd 31, Isd 38 and 34 (Table 1).

Significantly the highest quantity of chlorophyll 'total' was found in Isd 32(3.06 mg/gfw) followed by Isd 37 and Isd 40. Significantly the lowest quantity ofchlorophyll 'total' was recorded in Isd 35 (1.01 mg/gfw) followed by Isd 36 andIsd 38. The chlorophyll 'total' in Isd 31 (2.12 mg/gfw) and Isd 33 (2.09 mg/gfw)was statistically similar (Table 1).


68

Table 1. Leaf chlorophyll (a, b and total) content at vegetative stage and stemborer (SB) infestation in different sugarcane

Varieties Mean chlorophyll (mg/g fresh weight) contents SB infestationChlorophyll ‘a’ Chlorophyll ‘b’ Chlorophyll ‘total’ (%)

Isd 31 1.75 b 0.38 d 2.12 c 3.53 bcIsd 32 2.60 a 0.79 a 3.06 a 9.58 aIsd 33 1.60 c 0.48 c 2.09 c 2.76 cIsd 34 1.59 cd 0.44 cd 2.03 cd 5.56 bIsd 35 0.81f 0.18 f 1.01 g 2.49 cIsd 36 1.33 e 0.46 c 1.81 e 2.57 cIsd 37 1.73 b 0.58b 2.32 b 3.70 bcIsd 38 1.53 d 0.43 cd 1.96 d 2.63 cIsd 39 0.83 f 0.29 e 1.12 f 2.09 cIsd 40 1.64 c 0.62 b 2.26 b 3.02 cCV (%) 1.91 2.72 1.87 12.76

Means within a column followed by the same letter(s) are not significantly different (P=0.05)according to DMRT.

Data presented in Table 1 showed that the highest (9.58%) infestation bysugarcane stem borer was found in Isd 32 and the lowest (2.09%) in Isd 39.Similarly, maximum chlorophyll content (a, b and total) was found in Isd 32 andthe minimum in Isd 39Relationship of stem borer infestation with chlorophyll content: The percentstem borer infestation was positively correlated with the content of chlorophyll 'a'(Fig.1.A), chlorophyll 'b' (Fig.1B.) and chlorophyll 'total' (Fig.1.C.). Therelationship indicated that the contents of chlorophyll 'a', chlorophyll 'b' andchlorophyll 'total' influence on the infestation of sugarcane stem borer.The results of this study corroborated with the work of Begum et al. (2012) whoreported that à`, `b` and 'total' chlorophyll content was positively correlated withpercent stem borer infestation in sugarcane. Mazed (2011) also showed that à`, `bànd 'total' chlorophyll content in okra were positively correlated with shoot andfruit borer infestation. In their study Prodhan et al. (2006) found positiverelationship between chlorophyll content in brinjal leaf and brinjal shoot and fruitborer infestation.


69


70

Fig.1. Relationship between stem borer infestation with (A) chlorophyll à`, (B)chlorophyll `b` and (C) `total` chlorophyll content in sugarcane leaves

Nutrient content: Total N content ranged from 1.18 to 2.34% in differentsugarcane varieties. Significantly the highest nitrogen content was found in Isd 34,followed by Isd 38 (2.21%) and Isd 40. Significantly the lowest nitrogen wasfound in Isd 35 follwed by Isd 33, Isd 37 and Isd 39. The highest phosphoruscontent (0.20%) was also found in Isd 34 followed by Isd 36 (0.14%) and Isd 40,the results were significantly different. The lowest P content (0.08%) was observedin Isd 32, which was statistically similar to Isd 33. Phosphorus content in Isd 33(0.09%), Isd 35 (0.10%), Isd 31, Isd 37 and Isd 39 (0.11%) were statisticallyidentical but significantly higher compared to Isd 32 and Isd 33. Content ofpotassium ranged from 1.38% to 1.46% in sugarcane varieties. The maximum Kcontent was recorded from Isd 31, Isd 32, Isd 33 and Isd 38, which werestatistically similar to Isd 39 (1.45%). The lowest (1.38%) K content was found inIsd 40. The calcium content varied from 0.30% to 0.46% in sugarcane varieties.Calcium content was maximal (0.46%) in Isd 34, which was statistically similar toIsd 32 (0.41%), Isd 36, Isd 38, Isd 39 and Isd 40 (0.40%). The lowest (0.30%) Cacontent was found in Isd 33, which was statistically similar to Isd 31 and Isd 35.The Mg content ranged from 0.13% to 0.23% in different sugarcane varieties andsignificantly higher amount of Mg was found in Isd 40 which was statisticallyidentical with Isd 32 and Isd 34. The lowest Mg content was found in Isd 35. Thehighest (0.17%) Na was obtained in Isd 34 and the lowest (0.10%) was found inIsd 35 (Table 2). The lowest infestation was found in Isd 35 and the highestinfestation was recorded Isd 34 (Table 2).

Table 2. Content of nutrient elements in leaves of different sugarcane varieties atvegetative stage and stem borer infestation

Varieties Content of nutrient element in sugarcane leaves (%) SB Total N P K Ca Mg Na infestation (%)

Isd 31 1.19 fg 0.11 d 1.46 a 0.31 cd 0.20 ab 0.12 ab 5.53 cdIsd 32 1.90 c 0.08 e 1.46 a 0.41 ab 0.22 a 0.13 ab 6.56 cdIsd 33 1.31 ef 0.09 de 1.46 a 0.30 d 0.19 abc 0.13 ab 5.76 cdIsd 34 2.34 a 0.20 a 1.43 c 0.46 a 0.23 a 0.17 a 11.60 aIsd 35 1.18 g 0.10 d 1.42 c 0.34 bcd 0.13 c 0.10 b 4.49 dIsd 36 1.91 c 0.14 b 1.44 bc 0.38 abc 0.18 abc 0.13 ab 9.58 abIsd 37 1.32 e 0.11 d 1.45 ab 0.35 bcd 0.19 ab 0.11 ab 7.72 bcIsd 38 2.21 b 0.12 cd 1.46 a 0.38 abc 0.21 ab 0.13 ab 9.45 abIsd 39 1.62 d 0.11 d 1.45 ab 0.39 ab 0.16 bc 0.11 ab 5.30 cdIsd 40 1.99 c 0.13 c 1.38 d 0.40 ab 0.23 a 0.13 ab 9.47 abCV (%) 1.00 4.29 3.16 1.12 5.99 3.67 12.29


Relationship of stem borer infestation with nutrient elements: A positiveand linear relationship was observed between rate of stem borer infestation andtotal N & P content (Fig.2 A, B). The relationship suggested that stem borerinfestation weas dependent on the total N. A negative linear relationship wasobserved between sugarcane stem borer infestation and % K (Fig.2.C). Thissuggests that stem borer infestation is less dependent on the % K in plants. Stemborer infestations with Ca, Mg and Na content in sugarcane varieties were positiveand linear (Fig. 2 D, E & F). Findings of the present study revealed that infestationof sugarcane stem borer was positively correlated with the content of total N, P,Ca, Mg and Na in sugarcane varieties, whereas the infestation of sugarcane stemborer was negatively correlated with K content. Similar findings were alsoreported by many other workers (Wood 1984, Abayomi 1987, Rahman et al. 1992,Banger et al. 1994, Afolobi, 1988, Bokhtiar & Sakurai 2003; Dang et al. 1995).They reported that the presence of different nutrient elements in sugarcane leavesinfluence stem borer infestation.


71

Fig.2.Relationship of stem borer infestation with (A) total N, (B) P, (C) K, (D) Ca,(E) Mg and (F) Na content in sugarcane leaves

Sugar and fibre content: The total sugar content in ten sugarcane varieties rangedfrom 0.57 to 1.08%. Significantly the highest total sugar was obtained from Isd 34.The lowest total sugar was found in Isd 35. The highest (0.54%) reducing sugarcontent was found in Isd 32 and the lowest (0.20%) was found in Isd 34. The pol% cane varied from 11.49% to 13.85% in different varieties. The highest (13.85%)


72

pol % cane was obtained from Isd 34 and the lowest (11.49%) pol % cane wasfound in Isd 32. The maximum fibre content was found in variety Isd 37and theminimum was recorded from variety Isd 38 (Table 3). The lowest reducing sugar is desired for sugarcane production under commercialfield condition (Chen 1985, Beniwal et al. 1989), and the lowest fiber percentageis necessary for better sugarcane production (Islam 1984, Jabber et al. 2005).Islam (1984) reported that higher fiber content leads to higher baggasse productionand pol losses in baggasse. Table 3. Sugar and fiber content in different sugarcane varieties and stem borer

infestation

Varieties Mean sugar and fiber content of sugarcane leaf/stem (%) SB Total sugar Reducing Pol of cane Fibre infestation

sugar (%)Isd 31 0.67 fg 0.43 ab 11.94 de 16.30 a 5.53 cdIsd 32 0.68 efg 0.54 a 11.49 e 16.00 ab 6.56 cdIsd 33 0.81 cde 0.40 bc 12.38 cd 14.90 bc 5.76 cdIsd 34 1.08 a 0.20 d 13.85 a 14.70 bc 11.60 aIsd 35 0.57 g 0.25 d 12.87 bc 15.30 abc 4.49 dIsd 36 0.78 def 0.27 cd 13.02 bc 16.32 a 9.58 abIsd 37 0.95 b 0.39 bc 13.30 ab 16.58 a 7.72 bcIsd 38 0.92 bc 0.41 b 13.24 ab 14.38 c 9.45 abIsd 39 0.73 ef 0.30 bcd 11.75 de 16.05 ab 5.30 cdIsd 40 0.89 bcd 0.39 bc 13.36 ab 14.55 c 9.47 abCV (%) 5.41 4.64 4.52 3.95 12.29


Relationship of stem borer infestation with sugar and fibre content: Apositive and linear relationship was obtained between stem borer infestation andtotal sugar % (Fig.3.A). This suggests that stem borer infestation is dependent onthe percent total sugar in the varieties.

A negative and linear relationship was obtained between sugarcane stem borerinfestation and reducing sugar (Fig.3.B). This suggests that stem borer infestationis less dependent on reducing sugar in the varieties.


73

A positive as well as linear relationship was obtained between stem borerinfestation and pol % cane (Fig.3.C) suggesting stem borer infestation dependenton the pol % cane in the varieties.

A negative and linear relationship was observed between percent sugarcanestem borer infestation and fiber % in cane (Fig.3.D). This suggested that stemborer infestation was less dependent on the fiber % in cane varieties.

Stem borer infestation was positively correlated with % total sugar and pol %cane of sugarcane but negatively correlated with % reducing sugar and fiber % invarieties. Rahman and Alam (1987), Kumar et al, (1972) and Habib & Alireza(2010) conducted several studies and found that % total sugar, pol % cane, %reducing sugar and fiber % in cane, were positively correlated with percent stemborer infestation.

Fig.3.Relationship between stem borer infestation and (A) total sugar (B) reducingsugar, (C) pol ( %) cane and (D) fiber (%) in different sugarcane varieties


74

CONCLUSIONThe biochemical constituents like chlorophyll at the higher level in Isd 32positively influenced sugarcane stem borer infestation. The presence of higheramount of total sugar (1.08%), pol % cane (13.85%) and lower amount of reducingsugar (0.20%), fiber % (14.38%) were recorded in Isd 34 which showed positivecorrelation with stem borer infestation. Other biochemical constituents likenitrogen (2.34%), phosphorus (0.20%), calcium (0.46%), magnesium (0.23%) andsodium (0.17%) were higher in Isd 34 which showed positive correlation with theinfestation of stem borer. These findings indicated that Isd 34 is a higher nutrientcontent variety in comparison to other nine varieties but susceptible to stem borerinfestation. So the variety Isd34 should be recommended for cultivation wherestem borer is a minor pest.

REFERENCES

ABAYOMI, A.Y. 1987. Growth, yield and crop quality of sugarcane cultivar Co957 under different rates of application of nitrogen and potassium fertilizers.J. Agric. Sci. (Cambridge), 109, 285-292.

AFOLOBI, S.S. 1988. Effects of nitrogen fertilizer on sugarcane yield and juicequality in Bacita. Bangladesh J. Sugarcane. 10, 59-62.

ARNON, D.I. 1949. Copper enzymes in isolated chloroplasts. Polyphenol-oxidasein Beta vulgaris, Plant Physiol. 24, 1-15.

BANGER, K.S., MAINI, A. & SHARMA, S.R. 1994. Effect of fertilizer nitrogenand press mud on growth, yield and quality of sugarcane. Crop Res. 8, 23-27.

BARC (BANGLADESH AGRICULTURAL RESEARCH COUNCIL). 2005.Fertilizer Recommendation Guide. Published by BARC, New Airport Road,Farmgate, Dhaka-l215. pp. 97-136.

BEGUM, M. K., ALAM, M.R., ISLAM, M.S. & AREFIN, M.S. 2012. Effect ofWater Stress on Physiological Characters and Juice Quality. J. Sugar Tech,14 (2): 161-167.

BENIWAL, M.S., SATYAVIR & TANEJA, A.D. 1989. Effect of red rot on juicequality of sugarcane . Indian Sugar. 31, 403-406.

BOKHTIAR, S.M. & SAKURAI, K. 2003. Sugarcane response to soilphosphorus. Better Crops International, 17: 20-25.


75

CHEN, J.C.P. 1985. Cane sugar handbook. A manual for cane sugar manufacturesand their chemists.11th ed. John Wiley and Sons, New York, Brisbane.Article 28.10, P793-805.

CHOWDHURY, M.K.U. & VASIL, I.K. 1993. Molecular analysis of plantsregenerated from embryogenic cultivars of hybrid cane cultivar. Theor. Appl.Genet. 86(2-3): 181-188.

DANG, Y.P., VERMA, K.S. & PANNU, B.S. 1995. Need for potassiumfertilization in sugarcane. Indian Sugar, XLV: 229-235.

FRY, J. 1997. A global perspective of sugar industry. pp. 1-16. In: Intensivesugarcane production: Meeting the challenge beyond 2000. Proceeding ofthe sugar 2000 symposium, 20-23 August Brisbane, Australia.

HABIB, A. & ALIREZA, A. 2010. Crop loss and Identification of Physical andBiochemical agents related to resistance in different sugarcane Cultivars tostalk borers. Advances in Environmental Biology. 4 (2): 234-240.

HORN, D.J. 1988. Ecological Approach to Pest Management. The Guilford press.New York, London. 285p.

ISLAM, M.A. 1984. Proceeding of workshop on sugarcane productiontechnology. April 12-14. 1984. 197p.

JABBER, M.A., GHAFUR, M.A., BEGUM, M.K. & AREFIN, M.S. 2005.Maturity status of new promising sugarcane Genotypes and evaluation forGur Quality. Bangladesh J. Sugarcane. 24-27 : 41-46.

KUMAR, A., ACIN, N.M. & ALEXANDER, A.G. 1972. Relationships ofchlorophyll and enzyme gradients to sucrose content of sugarcane leaves.Annals Report Agriculture Experiment, State University Puerto Rico (1970-1971).

MAZED, M.A. 2011. Study on the Bio-ecology of okra shoot and fruit borer andits integrated management. A PhD Dissertation, Entomology division,Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur-1706, Bangladesh. 223p.

PRODHAN, M.D.H., SHAJAHAN, M., QUMRUZZAMAN, A.K.M. &RAHAMAN, M.A. 2006. Chlorophyll content of brinjal leaf in relation toresistance for the shoot and fruit borer. Bangladeesh J. Agril. Res. 31(2):291-300.


76

RAHMAN, A.B.M.M. & ALAM, M.R. 1987. Association of Some LeafEndowments with the Sugar Content of Sugarcane. Bangladesh J.Sugarcane. 9 : 33-36.

RAHMAN, A.B.M M. &. PAL, S.K. 2003. Sugarcane Production Technologies inBangladesh. A Hand book. Bangladesh Sugarcane Research Institute(BSRI), Ishurdi, Pabna. Pp 54-566.

RAHMAN, M.H., PAL, S.K & ALAM, F. 1992. Effects on nitrogen, phosphorus,potassium, sulphur, zinc and manganese nutrients on yield and sucrosecontent in sugarcane in flood-plain soils of Bangladesh. Indian J. Agric. Sci.62 : 450-455.

RAUPP, M.J. & DENNO, R.F. 1983. Leaf age as a predictor of herbivoredistribution and abundance. Pp. 91-124. In: Denno, R.F. and M.S. Mcclure(ed.). Variable plants and Herbivores in natural and managed systems.Academic press, New York.

SOMOGYI, M. 1952. Notes on sugar determination. J. Biol. Chem. 195: 19-23.STEEL, R.G.D. & TORRIE, J.H. 1960. Principles and Procedures of Statistics.

McGraw Hill Book Co. Inc., New York. 481p.WITHAM, F.H., BLAYDES, D.F. & DEVLIN, R.M. 1986. Chlorophyll

absorption spectum and quantitative determination. pp. 128-131. In:Exercises in plant physiology. Boston.

WOOD, R.A. 1984. The role of nitrogen, phosphorus and potassium in theproduction of sugarcane in South Africa. Fert. Res. 29 : 89-98.

YAMAKAWA, T. 1992. Laboratory methods for Soil Science and Plant nutrition:Part 2-Methods of Plant Analysis of JICA-IPSA Project, Feb. 22, 1992.15pp.

(MS received for publication 02 February 2013)


77

79

DEVELOPMENT OF AN EFFECTIVE MASS REARING METHOD FORTRICHOGRAMMA EVANESCENS AND T. CHILONIS USING TWO

DIFFERENT HOSTSK. BEGUM1, S. N. ALAM1, M. Z. ALAM2, M. R. U. MIAH2, M. I. H. MIAN3

& M. M. HOSSAIN4

1Division of Entomology, Bangladesh Agricultural Research Institute, Gazipur;2Department of Entomology, 3Department of Plant pathology; 4Department ofHorticulture; Bangabandhu Sheikh Majibur Rahman Agricultural University,

Salna, Gazipur, Bangladesh

ABSTRACTA study was undertaken to develop an effective mathod for mass rearing ofTrichogramma evanescens and T. chilonis under laboratory condition and toassess the effect of parasitoid age and the age of host eggs to ensure maximumparasitization. The parasitoids were reared on eggs of Sitotroga cerealella andCorcyra cephalonica under 27±2°C, 65±5% RH and natural photoperiod. Theresults showed that adult emergence exceeded 90% on both the hosts and eggparasitizations ranged from 81.13 to 94.47%. The adult longevity and emergencerates ranged from 4.1 to 4.5 days and 90.86% to 91.13%, respectively. Theoverall results manifested no significant difference. Higher egg parasitism wascaused by T. chilonis reared on C. cephalonica eggs (94.47%) compared to T.evanescens (93.87%). Effect of different ages (8, 16, 24 h) of eggs on parasitismdid not differ significantly. In both the studies, the developmental period of T.evanescens inside the host eggs remained almost similar, while the 24 h old T.evanescens parasitized eggs (96.75%) was followed by 48 h old parasitoids(87.25%). Use of younger parasitoids and host eggs were found better forparasitization. The suitable age of host eggs was found to be 8-24 h to achievemaximum parasitization for large scale production of T. evanescens. It was alsofound that under laboratory conditions, both T. evanescens and T. chilonis wereeffective for rearing. Keywords: Parasitoid, Trichogramma spp., mass culture, Sitotroga cerealella,Corcyra cephalonica.

INTRODUCTIONTrichogramma evanescens and T. chilonis (Hymenoptera: Trichogrammatidae)

are widely distributed egg parasitoids. They attack eggs of several lepidopterouspests and are used as major biological control agents. Rearing parasitoids isnecessary for experimental purpose and for potential mass release in the field.Selecting a suitable host is critical for developing a successful rearing method. If


other conditions are favourable, the rate of population increase will be a suitableindicator of parasitoid performance on different hosts.

Wasps of the genus Trichogramma are extensively used as biological controlagents because of their ability to attack eggs of several lepidopterous pests thatcause serious damage to agricultural crops (Greenberg et al. 1998a). Inoculative oraugmentative release programs for the control of pests, natural enemies should bemass propagated (Sun et al. 1990). In many cases, fictitious hosts have beenwidely used for mass production of Trichogramma species to reduce costs.However, mass-rearing programs have often resulted in adaptation of the insectunder laboratory conditions.

Trichogramma requires eggs of some hosts on which it can lay eggs. The eggsof the lepidopteran pests are the general media for parasitization of Trichogrammaspp. When the larvae hatch, they use the eggs of the host as a food source. The ricemoth, Corcyra cephalonica ( Stainton) and Sitrotoga cerealella (Olivier) are oftenused as hosts for mass rearing of Trichogramma. The mass rearing ofTrichogramma thus depends on the mass rearing of C. cephalonica and/or S.cerealella. Many studies on Trichogramma have been conducted to observe theparasitizing potential, searching ability and insect pest suppression during forseveral years. For successful release and to improve fitness parameters ofparasitoids under natural field condition there is need to develop qualityparasitoids through studies (Nadeem et al., 2004). For better adaptations of naturalenemies in the field and in vitro studies are also necessary. Pak & Van Lenterene(1988) reported that the Trichogramma strains performed well in the laboratoryand also have the ability to adapt in field conditions.

For biological control of pests at their egg stage, egg parasitoids are best suitedbiocontrol agents which require mass-production for augmentation in the field. Inmass production, proper species, potential strain, cost effectiveness, etc becomesvital. Mass production of egg parasitoids on natural host insects is very difficult asmass production of the host insect is very expensive. Normally, parasitoids aremass-reared on a relatively small factitious host and then released to attack a largertarget host (Bourchier et al. 1994). Trichogramma sp. is considered as an effectiveegg parasitoid and can be used in the augmentation process. For this reason,development of an easy and cost effective mass rearing method is essential. Theage of host eggs affect the Trichogramma production at least in two ways. Firstly,the oviposition preference of the parasitoid females (Pak, 1986) and secondly, asan indicator of the resource quality available for the developing parasitoid larvae,

K. BEGUM, S. N. ALAM, M. Z. ALAM, M.R.U. MIAH, M. I. H. MIAN & M. M. HOSSAIN

80

which affect the physiology of host parasitoid interaction (Vinson & Iwantsch1980). Similarly, the age of ovipositing Trichogramma is also important inattaining optimum parasitization of host eggs. Considering the above facts, thepresent study was undertaken (i) to develop an economic and effective mathod formass rearing of T. evanescens and T. chilonis under laboratory condition and (ii)to assess the effect of parasitoid age and the age of host eggs to ensure maximumparasitization.

MATERIALS AND METHODSThis study was carried out in the IPM laboratory of Entomology Division,

Bangladesh Agricultural Research Institute, Gazipur, Bangladesh during March -May, 2010.Collection of laboratory host eggs: The eggs of S. cerealella and C. cephalonicawere used. Fresh egg masses of the moths were collected and reared on wheatgrain in a special (moths were collected automatically from moth rearing chamber)mass-rearing chamber. For collection of C. cephalonica eggs, 100 adults were kept(by maintaining 1:1 sex ratio) in a plastic container (3500 cc) fastened with 32mesh net on its mouth. Some wire nets were placed inside the plastic container forlaying eggs of the moths. The adult moths were kept in the container for one dayfor mating and subsequent egg laying. Next day, the adults and their body partswere removed from the container. The fresh eggs were collected on a clean paperby shaking and putting down the top of the container.

To collect the eggs S. cerealella, thousands of adults were caught from the S.cerealella mass-rearing chamber and kept in a glass cylinder (3000 cc). The mouthof the cylinder was covered with 32 mesh net. Adults were released in the cylinderfor one day for mating and subsequent egg laying. Eggs laid on the wall of thecylinder were brushed and sieved to collect fresh eggs with body parts of moth.The body parts were cleaned by holding the sieve near an exhaust fan to get thefresh eggs only. The collected eggs of both hosts were kept into different test tubes(3cm × 15cm).Collection of Trichogramma spp.: Two Trichogramma spp. (T. chilonis and T.evanescens) were used in this study. These were initially obtained as pupae in eggcard from the IPM laboratory of the Entomology Division of BARI.Preparation of eggs strips: For preparing the egg strips, i) paper strip (10 cm x 1cm) with different colour (white for S. cerealella and light green for C.cephalonica) and labeling, ii) acacia powder of Acacia arabica, iii) distilled water,

Mass rearing method for Trichogramma evanescens and T. chilonis

81

iv) small Petri dish, and v) dropper were collected. At first 10% acacia gum wasprepared in a small Petri dish by mixing acacia powder with distilled water.Mixing of water was done very carefully with a dropper to maintain properviscosity of the gum so that it could hold the host eggs firmly on the paper strip.

One thousand five hundred eggs of each host were counted separately. Onehundred fresh eggs were counted and kept on a paper sheet (10 cm × 10cm)separately for each host. In this way, total 1500 eggs of each host were divided into15 parts. To make the host egg strip, a small amount of acacia glue was carefullypressed on the front side of the labeled paper strip. Previously counted 100 eggswere placed carefully on the glued portion of the strips so that there would be onlyone layer of eggs on the strip. After preparation, the strips were properly labeledwith date, host name, parasitoid name and number of eggs present per strip.

Trichogramma stock cultures: Emerged parasitoids were maintained in eggsof S.cerealella. These were used as hosts and reared in the IPM laboratory ofEntomology Division of BARI. S. cerealella eggs were glued with gum Arabic(diluted in water at 30%) into a white cardboard (10 cm x 1cm) and inserted intoa glass tube (15 cm × 2.5 cm). The eggs were exposed to Trichogramma, the tubesclosed with cotton wool and placed on a wooden holder until adults emerged.Parasitoid cultures were maintained at 27±2ºC, 65±5% RH and naturalphotoperiod.

The parasitism efficiency of T. chilonis and T. evanescens was evaluated on S.cerealella and C. cephalonica eggs. For the parasitization, one strip containing 100host eggs of each host and five pairs of Trichogramma sp. were placed together inindividual test tube (15 cm × 3 cm). Strips with pupae which were almost ready toemerge were taken from the reared colony stock of Trichogramma in the IPMlaboratory in the form of a strip containing 100 pupae of Trichogramma/strip in S.cerealella or C. cephalonica eggs. In this way, 30 strips with eggs (15 with eggs ofS. cerealella and 15 with eggs of C. cephalonica) were parasitized by those twospecies of Trichogramma @15 strips of each host eggs with one species ofTrichogramma. The test tubes, each containing one host egg strip and one speciesof Trichogramma adult were placed in the parasitization chamber after properlabeling with date, number of eggs, host name, and parasitoid name.

Another study was undertaken to find out the effects of parasitoid and host eggage on parasitism by Trichogramma sp. For this purpose T. evanescens was rearedon the eggs of S. cerealella. Wheat grains were used as a rearing medium for S.


82

cerealella. The moths were collected through automatically moth collectionchamber/ device and caged in oviposition chambers (3000cc of glass cylinder witha wire net). Eggs of S. cerealella were collected daily by sieving the eggs. Eggcards were prepared by gluing S. cerealella eggs to paper cards (10 cm ×1 cm) andexposed to T. evanescens in a glass tube (15cm× 3cm) for 72 h or until the adultsdied. The parasitoids were fed 50% honey solution provided as small drops on thewalls of the glass tube. The cards were kept under controlled conditions (27 ± 2oC,natural light and dark and 65±5% R.H.) for use in the study.Effect of the age of S. cerealella eggs on oviposition preference of T.evanescens: Sitotroga cerealella eggs of 8, 16, 24, 48, and 72 h of age wereexposed for parasitization by T. evanescens females in a no-choice experiment. Aprepared egg card containing 100 host eggs of each age was introduced in aparasitization glass tube containing 5 pairs (male and female) of freshly emergedvirgin less than 1 day old T. evanescens and removed after the death of adultfemale. The parasitized egg card was maintained at 27 ± 2oC, natural photoperiodand 65± 5% R.H until melanization of the parasitized eggs. The parasitized andunparasitized eggs were counted and the percent parasitism of S. cerealella eggswas calculated. LSD test was performed for mean comparison after ANOVA. Parasitism of S. cerealella eggs as influenced by the age of the female T.evanescens: In this study, the effect of age of T. evanescens female on the extentof parasitization of S. cerealella was investigated. Female T. evanescens of 4 agegroups (24, 48, 72, and 96 h after emergence) were used in this study. Fresh eggs(4 - 6 h old) of S. cerealella were glued on hard paper cards (10 cm ×1 cm) @ 100eggs per card. Five couples for each age group of T. evanescens were introducedinto each of the glass tubes (15 cm × 2.2 cm) containing a prepared egg card andallowed to parasitize until death of adult parasitoids. The egg card was thenremoved and the extent of parasitism was noted by counting the total number ofthe parasitized and unparasitized eggs. LSD test was performed for meancomparison after ANOVA.

RESULTS AND DISCUSSION

Parasitism efficiency of two Trichogramma spp. on two hosts' eggs: There wasno significant difference between the percent egg parasitization of two hosts, S.cerealella and C. cephalonica by T. evanescens and T. chilonis. Percent eggs


83


84

parasitization on S. cerealella and C. cephalonica by T. evanesecns and T. chiloniswere 81.13, 93.86, and 84.6, 94.47, respectively (Table 1). Adult parasitoid emergence from parasitized eggs also did not differ significantly.The highest adult emergence of T. evanescens from parasitized eggs of S.cerealella was 91.31% and it was almost similar with T. chilonis parasitization onthe eggs of S. cerealella (90.98%) and C. cephalonica (90.86), respectively.Greenberg et al. (1998b) showed that adult female parasitoid depended on the sizeof the rearing host egg in which the insect developed. There are reports ofincreased size being associated with increased fitness of the parasitoids, measuredas success in locating hosts (Bennett & Hoffmann, 1998) and with increasedfecundity (Greenberg et al. 1998c). The size of egg of C. cephalonica is slightlylarger than that of S. cerealella. The adult longevity varied from 4.1 to 4.5 days.Development of only one parasitoid per egg was observed from both the egg understudy. Overall results manifested no significant difference among the biologicalparameters (Table 1).

Table 1. Parasitism efficiency of two Trichogramma spp. on the eggs of S.cerealella and C. cephalonica

Host Parasitoids % Egg % Adult Adult longevity No. ofparasitization emergence (days) parasitoid/(Mean ± SE ) (Mean ± SE) (Mean ± SE) egg

S. cerealella T. evanescens 81.13±1.18 91.31±0.42 4.21±0.39 1T. chilonis 84.6±0.58 90.98±0.66 4.19±0.33 1

C. cephalonica T. evanescens 93.86±0.88 90.99±0.30 4.5±0.27 1T. chilonis 94.47±0.70 90.86±0.49 4.55±0.31 1

Level of significance ns ns ns ns

Hoffmann et al. (2001) evaluated the performance of parasitoid, T. ostriniae, onthe eggs of four factitious host, Ostrinia nubilalis, S. cerealella, Trichoplusia niand evaluated S. cerealella as an intermediate host for rearing of the parasitoid ascompared to the other hosts and in the present results, these were nearly equal afterrearing on both S. cerealella and C. cephalonica. Similarly Nathan et al. (2006)evaluated the emergence and survival of adult T. chilonis by using host eggs of C.cephalonica and showed that S. cerealella rearing on other hosts can give desiredresult. The present studies showed that S. cerealella and C. cephalonica areequally good for the rearing of T. chilonis and T. evanescens.

Often, insects other than the target hosts are used to reduce the cost or increasethe efficiency of mass production of parasitoids. However, even for a polyphagousparasitoid, the suitability of these factitious hosts may vary greatly. Characteristicssuch as host egg volume, chorion thickness, nutritional content, age, and eggdistribution can affect rates of parasitism as well as the number, quality, and sexratio of parasitoids (Greenberg et al. 1998).

Higher egg parasitism occurred by T. chilonis on the host eggs C. cephalonica(94.4.0%) than T. evanescens (93.87%). The same trend of egg parasitism by twodifferent species of Trichogramma was also observed on the host eggs, S.cerealella. Higher egg parasitism was done by T. chilonis (84.6%) followed by T.evanescens (81.13%) (Table1).

The mean parasitisms of S. cerealella eggs at the age of 8, 16 and 24 h were95.75, 95.50 and 96.00%, respectively. The parasitisms at three lower ages werestatistically similar but significantly higher compared to two higher ages (48 and72 h). The lowest parasitism (71.50%) was recorded when age of eggs was 72 h.The results indicate that T. evanescens could not discriminate host eggs up to theage of 24 h. However, T. evanescens liked eggs of 48 h than the eggs of 72 h.Irrespective of age of the host eggs the duration of developmental period was 8days. It indicated that influence of age of host eggs within the range 8-96 h on thedevelopmental period of the parasitoids was identical (Table 2).

Table 2. Effect of the age of S. cerealella eggs on oviposition preference of T.evanescens

Age of eggs (h) Developmental period (days) Mean parasitism * (%)8 8 95.75 ± 0.25a16 8 95.5±0.64 a24 8 96.0±0.82a48 8 82.75±0.85b72 8 71.50±0.96 c

* Means within a column followed by common letter are not significantly different (P=0.05).

Table 3 showed that the mean parasitism was 96.75, 87.25, 83.75 and 63.00%when T. evanescens parasitized the host eggs at the age of 24, 48, 72 and 96 hours.The differences in parasitism of host eggs by the parasitoid were significant. The


85

developmental period of T. evanescens inside the host eggs of different age wasidentical (8 days).

Table 3. Parasitism of S. cerealella eggs as influenced by the age of female T.evanescens

Age of parasitoids (h) Developmental period (days) Mean parasitism*(%)eggs of T. evanescens

24 8 96.75±0.65a

48 8 87.25±0.65b

72 8 83.75±0.83c

96 8 63.0±0.82d* Means within a column followed by uncommon letter are significantly different (P=0.05).

Findings of the present study reveal that it is better to use younger parasitoids tofacilitate parasitization for Trichogramma mass production. Boivin & Lagace(1999) found that under laboratory conditions, T. evanescens female deposited56.00% of their eggs during the first 24 h and survival in the field did not exceed24 - 48 h. The result suggests that the parasitoid age of 8 - 24 h is quite suitable toachieve the maximum parasitism of host eggs for mass production of T.evanescens (Table 3). Zahid et al. (2007) reported that parasitism of S. cerealellaeggs by T. chilonis was influenced by host egg age and age of the female parasitoidand suggested to use younger Trichogramma for parasitization to get the highestyield of parasitoid. The Association of Natural Biocontrol Producers and the InternationalOrganization of Biological Control Subcommittee on Quality Control hasdeveloped quality control standards for Trichogramma and other natural enemies(Bigler et al. 1997). Standards for established culture on Sitotroga are 80.00% eggparasitization, 90.00% adult emergence and a sex ratio of 1.2 to 1.5 females permale (Greenberg et al. 1996). In this study, both the hosts followed this standardto establish culture of T. evanescens and T. chilonis. Based on the present results,the most appropriate host species for laboratory rearing of T. evanesens and T.chilonis could be mass reared most economically. It may be concluded that therearing techniques used for both parasitoid and host are acceptably productive andadequate to get required amount of parasitoids. For the highest parasitoid


86

production, it is important to use younger host eggs and Trichogramma forparasitization at standard level.

REFERENCES

BENNET, D. O. M. & HOFFMANN, A.A. 1998. Effect of size and fluctuatingasymmetry on field fitness of the parasitoid Trichogramma carverae. J. AnimalEcol. 67, 580-591.

BIGLER, F., SUVERKROPP, B.P.& CERUTI, F. 1997. Host searching byTrichogramma and its implications for quality control and release techniques. pp.71-86. In: Ecological Interactions and Biological control (eds. D. A. Andow, D.W. Ragsdale and R. F. Nyvall).

BOIVIN, G. & LAGACE, M. 1999. Effect de la taille sur la fitness deTrichogramma evanescens (Trichogrammatidae: Hymenoptera). Ann. Soc.Entomol. France. 35, 371-378.

BOURCHIER, R.S., SMITH, S.M., CORRIGAN, J.E. & LAING, J.E. 1994.Effect of host switching on performance of mass-reared Trichogramma minutum.Biocont.Sci. Technol. 4, 353-362.

GREENBERG S.M., NORDUND D.A. & WU, Z. 1998c. Influence of rearinghost on adult size and ovipositional behavior of mass produced femaleTrichogramma minutum Riley and Trichogramma pretiosum Riley (Hymenoptera:Trichogrammatidae). Biol. Contr. 11, 43-48.

GREENBERG, S. M., LEGASPI, J.C., NORDLUND, D. A., Wu, Z,.,LEGASPI, X & SALDANA, R.. 1998a. Evaluation of Trichogramma spp. againsttwo pyralid stemborers of Texas sugarcane. J. Entomol. Sci. 33, 158-164.

GREENBERG, S. M., NORDLUND, D. A., & WU, Z. 1998. Influence ofrearing host on adult size and oviposition behavior of mass produced femaleTrichogramma minutum Riley and Trichogramma pretiosum Riley (Hymenoptera:Trichogrammatidae). Biol. Contr. 11, 43-48.

GREENBERG, S. M., MORRISON, R. K.., NORDLUND, D. A. & KING, E.G. 1998b. A review of the scientific literature and methods for production offactitious hosts for using in mass rearing of Trichogramma spp. (Hymenoptera:Trichogrammatidae) in the former Soviet Union, the United States, westernEurope and China. J. Entomol. Sci. 33, 15-32.

Development of an effective mass rearing method for Trichogramma evanescens and T. chilonis

87

GREENBERG, S.M., NORDUND, D.A. & KING, E.G. 1996. Mass productionof Trichogramma spp.: Experience in the former Sovet union, china, United Statesand western Euroupe. Biocontrol News Inform. 17(3), 51-60.

HOFFMANN MP, ODE PR, WALKER DL, GARDNER J, VAN NOUHUYSS, & SHELTON AM. 2001. Performance of Trichogramma ostriniae(Hymenoptera: Trichogrammatidae) reared on factitious host, including the targethost Ostrinia nubilalis. Biol. Contr. 21, 1-10.

NADEEM, S., HAMED, M. & SIDDIQUI M.T. 2004. Dispersal andparasitizing potential of Trichogramma chilonis Ishii in early and late sown varietyNIAB- Karishma. The Nucleus. 39, 111-114.

NATHAN, S.S., KALIVANI, K., MANKIN, R. W. & MUHUGAN, K. 2006.Effect of millet, wheat, rice and sorghum diets on development of C. cephalonicaand its suitability as a host for Trichogramma chilonis. Environ. Entomol.,35, 784-788

PAK, G.A. 1986. Behavioral variation among strains of Trichogramma spp: Areview of the literature on host selection. J. Applied Entomol. 101, 55-64.

PAK, G.A. & VAN LENTERENE, J. C., 1988. Criteria and methods for the prerelease evaluation of different Trichogramma spp. strains. Proc. 2nd Intl. Symp.Trichogramma, Guangzhou, PR China, No. 43 Lescolloques de I'INRA, Paris,pp.442-443.

SUN, X., TAN, Y. & CHEN, J.1990. Study of the utilization of Trichogrammadendrolimi to control the masson pine moth Dendrolimus punctatus at longshanforest farm. Forest Res. 3, 407-410.

VINSON, S.B. & IWANTSCH, G.F. 1980. Host regulation by insectparasitoids. Quarterly Review Biol. 55,143-165.

ZAHID ,M., FARID, A, SATTAR, A & KHAN, I. 2007. Effects of parasitoidand host egg age on parasitism by Trichogramma chilonis (Ishii). Suranaree J. Sci.Technol. 14(4), 381-384.



88

89

ABUNDANCE AND DIVERSITY OF INSECT PESTS AND NATURALENEMIES IN COASTAL RICE HABITAT

M. M. H. KHAN

Department of Entomology, Patuakhali Science and Technology UniversityDumki, Patuakhali, Bangladesh, E-mail: [email protected]

ABSTRACTTwo studies were conducted to determine abundance and diversity of insectpests and natural enemies in coastal rice habitat in farmer's field at four locationsof Patuakhali district including Patuakhali Science and Technology University(PSTU) farm during July 2010 to January 2011. Results revealed that 7 differentinsect pests and 7 natural enemies were found in rice field during T. amanseason. The percent relative abundance of green rice leafhopper (GLH) andspider was the highest. Among the insect pest species, the population of GLHand short horned grasshopper was most prevalent in the rice field. Amongnatural enemies, damsel fly, spider and ichneumonid wasp were the mostprevalent while mirid bug, lady bird beetle and ground beetle were low in ricehabitat. The occurrence of insect pests and natural enemies was the highest atmaximum tillering stage and the lowest at early tillering stage. Abundance ofinsect pests and their natural enemies were more in high yielding rice varietiesnamely accession no. 20 as compared to local rice cultivars viz., Lalmota,moulata. Among 4 locations, the highest incidence of insect pest was observedat Patuakhali sader and the highest occurrence of natural enemies was atBauphal. Diversity indices of insect pests and natural enemies were variedaccording to habitat in T. aman season. Rice-rice habitat exhibited the lowestdiversity in respect to the Shannon's index (H) and evenness (J) for both insectpests and natural enemies compared to the other 3 habitats. The indices ofShannon's diversity index (H) and Pielou's evenness (J) for insect pest andnatural enemies were found highest in rice-banana habitat, whereas Margale'sindex of richness for insect pest was found highest in rice-banana habitat and fornatural enemies in rice-vegetable habitat. The value of D for both insect pestsand natural enemies was found highest in rice-banana habitat.

Keywords: Abundance, diversity, habitat, insect pest, natural enemies.

INTRODUCTIONRice is grown worldwide in over 124 million ha under diverse cultural

conditions over a wide geographical range (Heinrichs 1994). Traditional lowland


rice of Asia is photosensitive and ripened at the end of the monsoon, producingstable but low yields even under environmental extremes. Modern rice developedin the sixties to feed a growing human population and attain their high yieldingpotential with proper water management but are intolerant against drought orfloods (Litsinger 1989). In Bangladesh, rice fields are mainly monoculture, and thelack of ecological diversity could be the major cause of pest problems because thefood, hosts, prey and overwintering sites of most of the natural enemies of thepests are reduced, leading to limited natural bio-control. The continuous ricecultivation has created favourable condition for the insect pests. Moreover, theprevailing warm and humid climatic conditions of Patuakhali-Barisal regions havefavoured rapid multiplication of various insect pests and diseases. The yearlyestimated yield loss of rice in Bangladesh due to the attack of insect pests anddiseases amounts to 1.5-2.0 million tons (Siddique 1992). All of the fauna presentin the rice field are not harmful, some of them are beneficial. In most of the cases,natural enemies are able to interact with their prey or host populations and regulatethem at reasonably lower level than would occur otherwise. Ninety nine (99)species of parasitoids and 88 species of predators of rice insect pests have beenrecorded in Bangladesh (Wahiduzzaman 1993). The modern rice varieties aremore vulnerable to insect pests and have been recognized as major biotic stressesresponsible for significant reduction in yields of rice in different cropping systemof Bangladesh.

Hurlbert et al. (1989) studied the diversity of the arthropod communities inpaddy fields and found that the numbers of species and individuals, the values ofthe diversities and evenness were distinctly different according to habitat, type offield and growth stage of the rice. Modern farming systems which rely on within-field monoculture also discriminate against and reduce the activity of predatoryinsects because they lack ecological diversity (Hagen & Hale 1974). Some studieshave suggested that the size and composition of non-rice habitats adjacent to ricefields may have positive effects on natural enemies in rice fields (Xiaoping et al.1995). As the population development of some species in rice fields seems to berelated to non-rice habitats adjacent to rice fields (Chiu 1979), undoubtedly thebiodiversity of fauna and flora exerts an important role in integrated pest

M. M. H. KHAN

90

management of rice (Way & Heong 1994). In Bangladesh, the information on theinfluence of rice growth stages and ecological factors on the occurrence of insectpests and natural enemies in rice fields are very scanty. However, relatively littlework has been conducted on understanding how neighbouring crops affect pestecology. Therefore, the present study was conducted to assess the abundance anddiversity of insect pests and natural enemies in coastal rice habitats and to gatherinformation in order to develop elements of an integrated control program againstinsect pests of rice for use by the farmers in the local cropping system.

MATERIALS AND METHODS

Two studies were conducted in farmer's rice field at four upazilas viz., Dumki,Bauphal, Mirjagong and Patuakhali sader of Patuakhali district and PatuakhaliScience and Technology University (PSTU) farm during July 2010 to January2011.

Study 1: Four locations of Patuakhali district viz., Dumki, Bauphal, Mirjagongand Patuakhali sader were selected randomly to carry out the survey programme.Surveys were conducted in 10 randomly selected farmer's rice fields of eachlocation and Patuakhali Science and Technology University (PSTU) farm. Ricevarieties viz., lalmota, moulata, chinigura, HYV rice and Accession No. 20 wereincluded in this study at PSTU farm. Data were collected from rice seedling stageto harvest. The total developmental period of rice plant was divided into fourgrowth stages viz., early tillering, mid tillering, maximum tillering and panicleinitiation stages. The insect pests of rice and their natural enemies were observedand collected by a fine nylon cloth sweep net (30 cm diameter) and an aspirator.Sweeping was done from the plant canopy level including the interspaces betweenplants as well as close to basal region of the plants. In each field 10 completesweeps were made to collect the insect pests and their natural enemies. Samplingwas done at 7 days intervals at the above mentioned period during morning hoursat all study fields on all sampling dates. Ten samples were taken in every growthphase of rice plant for recording insect pests and natural enemies. Immediatelyafter collection, the samples were kept separately in labeled polyethylene bag. Theopen end of the polyethylene bag was closed with rubber bands. The collectedsamples of the insect pests and natural enemies of 10 complete sweeps from eachfield were preserved separately in labeled container/sample bottle. The samples

Insect pests and natural enemies in coastal rice habitat

91

were identified under magnifying glass. After that the collected samples wereproperly sorted and counted in the laboratory of the Department of Entomology,Patuakhali Science and Technology University, Dumki, Patuakhali. Study 2: The study was also conducted in farmer's rice field at four upazilasmentioned in study No. 1 including PSTU farm. The local rice variety viz.,Lalmota was grown in all the selected farmer's fields by the farmers in amanseason. All sorts of intercultural operations and crop management were done bythe farmers. No pesticide was used in the fields during the study period. To studythe relative abundance and species diversity of pests and natural enemies, fourhabitats were considered viz., rice-banana, rice-homestead, rice vegetables andrice-rice.

The insect pests of rice and their natural enemies were collected by the sameway mentioned in study No. 1. The collected samples were properly identified,sorted and counted under magnifying glass in the laboratory of the Department ofEntomology, PSTU. Data were analyzed following MSTAT program and meanswere separated by DMRT.Relative abundance of insect pests and natural enemies was calculated using thefollowing formula:

Total no. of each speciesRelative abundance (%) = _________________________ × 100Total no. of all species

Calculation of diversity indicesThe following indices were used to measure the diversity of insect pests andnatural enemies from the original data recorded from different rice habitat.Species diversityMenzies et al. (1973) define diversity as a community ecological concept which

refers to the heterogeneity in a community or assemblage of different organisms.Thus diversity is dependent upon the number of species present (Species richness,S) and the distribution of all individuals among the species (Equitability orevenness). To provide an overview of diversity, the Shannon-Weaver Index of Diversity was calculated (Shannon & Weaver 1963). The indexis expressed as-

STH= ____ Σ Pi log Pii= 1

M. M. H. KHAN

92

Where, Pi = the proportion of individuals in the ith species andST = the total species ni[ Pi = _____; ni = the number of individuals observed for each species andN N = the total number of individuals in each study area].

This index is based on information theory, where diversity is equated to theamount of uncertainty which exists as to the identity of an individual collected atrandom from a community. Species richnessTo provide a cohensive overview of species richness, Margalef's Index was alsocalculated along with S (actual number of species collected). Margalef's index(Margalef 1958) assumes a theoretical relationship between the number ofindividuals (N) and the number of species (S) in a sample and is expressed asfollows:

S-1M.I. = __________

logeNThe index logarithmically scales the value of S, and hence provides a means ofcomparison between stations with different ratios of S and N.

Equitability or EvennessEquitability is considered a component of diversity, in that it provides an ideaabout the evenness of species distribution at a site. Usually a positive correlationexists between diversity and equitability (Delong 1975) i.e. a high equitabilitywould indicate a high diversity and probably a 'healthy condition' of a fauna.Pielou's (1966) method of measuring equitability is most widely used. The computational formula is:

H J = ________

logeSWhere, H = Shannon's index

S = Total species collectedThe index value ranges from 0 to 1, with a value of 1 being the maximum possibleevenness in the community.


93

M. M. H. KHAN

94

Another diversity index was calculated using the Berger-Parker's DominanceIndex (d).

Nmaxd = _______

NTWhere, Nmax = the total no. of individuals of the most abundant species

NT = Total no. of individuals of all species collectedHence, the reciprocal form of the index is,

D= 1/d where, d= Berger-Parker's Dominance index (Southwood 1978).

RESULTS AND DISCUSSIONIncidence of insect pests and natural enemies in rice fields: Eight rice insectpests viz., stem borer, Scirpophaga incertulas; rice bug, Leptocorisa acuta; greenleafhoppers, Nephotettix spp.; short horned grasshoppers, Oxya spp.; long hornedgrasshoppers, Ucirtus spp.; leaf folder, Cnaphalocrosis medinalis andplanthoppers, Nilaparvata lugens and 7 natural enemies namely, damselfly,Agriocnemis spp.; ground beetle, Ophionea spp.; long jawed spider, Tetragnathaspp.; lynx spider, Oxyopes spp.; mirid bug, Cyrtohinnus lividipennis; ichneumonidwasp, Xanthopimpla spp. and lady bird beetle, Micraspis spp. were recordedduring study period (Table 1).

Relative abundance of insect pests and natural enemies in rice environment:The relative abundance of insect pests in rice environment during aman seasonwas in the rank order of green leafhopper (41.19%)>short horned grasshopper(18.10%)> long horned grasshopper (2.99)> stem borer (1.19%)>rice bug (0.60%)(Table 1). Similarly the relative abundance of natural enemies was in the rankorder of spider (14.33%)>damselfly (11.64%)>ichneumonid (6.27%)> mirid bug(2.39%)> and water bug (0.60%) (Table 2).

Population of insect pests and their associated natural enemies: Population ofinsect pests and their associated natural enemies at various growth stages of rice ispresented in Table 3. At early tillering stage, among insect pests, green leafhopper,brown planthopper (BPH) and among natural enemies, damselfly, spider and miridbug were recorded. At mid tillering stage, population of GLH was the highest andthe lowest was stem borer. In case of natural enemies, the spider population was


95

Table 1. Incidence of insect pests and natural enemies observed in T. Amanfarmers' rice fields.

Name of the insect pests Family Order1. Yellow stem borer (YSB) Pyralidae Lepidoptera2. Rice bug (RB) Alydidae Hemiptera3. Green leafhopper (GLH) Cicadellidae Homoptera4. Short horned grasshopper (SHGH) Acrididae Orthoptera5. Long horned grasshopper (LHGH) Tettigoniidae Orthoptera6. Leaf folder Pyralidae Lepidoptera7. Brown planthopper (BPH) Delphacidae HomopteraName of natural enemies Family Order1. Damselfly Conagrionidae Odonata2. Ground beetle (GB) Carabidae Coleoptera3. Long jawed spider (LJS) Tetragnathidae Araneae4. Lynx spider (LS) Oxyopiidae Araneae5. Mirid bug (MB) Miridae Hemiptera6. Ichneumonid Ichneumonidae Hymenoptera7. Lady bird beetle Coccinellidae Coleoptera

Table 2. Relative abundance of insect pests and natural enemies in rice habitat inaman season

Insect pests Relative abundance (%)Short horned grasshopper 18.1Long horned grasshopper 2.99Green leafhopper 41.19Stem borer 1.19Rice bug 0.60BPH 0.65Leaf folder 0.65Natural enemiesDamselfly 11.64Spider 14.33Ichneumonid 6.27Mirid bug 2.39Water bug 0.60Lady bird beetle 0.62

recorded as maximum followed by Ichneumonid while damselfly population wasminimum. At maximum tillering stage, the highest population of short hornedgrasshopper was observed followed by GLH and the lowest was the long hornedgrasshopper and was followed by stem borer and rice leaf roller. Among naturalenemies, the highest population of spider followed by damselfly and Ichneumonidwas recorded. On the other hand, the lowest was the Mirid bug followed bypredatory grasshopper. At panicle initiation stage, the highest population of GLHwas recorded which was followed by short horned grasshopper. The lowest was

M. M. H. KHAN

96

Table 3. Pest population and their associated natural enemies at various growthstages of T. Aman rice in coastal ecosystem

Sl. No. Growth stage/ Population of Pest Population of Natural enemies/phase /10 complete sweep 10 complete sweep

Insect Pest No. Natural enemies No.1 Early tillering GLH 16 Spider 6

stage BPH 1 Damselfly 11Predatory grasshopper 8Mirid bug 1

2 Mid tillering SHGH 7 Spider 16stage GLH 30 Damselfly 7

Stem borer 1 Ichneumonid 113 Maximum tillering SHGH 18 Spider 13

stage LHGH 2 Damselfly 12GLH 13 Predatory grasshopper 3Stem borer 2 Mirid bug 2Leaf roller 2 Ichneumonid 6

4 Panicle initiation SHGH 13 Spider 5stage LHGH 2 Damselfly 9

GLH 49 Water bug 2Stem borer 1 Mirid bug 5Rice bug 2 Ichneumonid 4

BPH-Brown Plant Hopper; SHGH-Short Horned grasshopper; LHGH-Long Horned Grasshopper;GRLH-Green Rice Leafhopper


97

the stem borer and this was followed by rice bug and long horned grasshopper.Among natural enemies, the highest population of damselfly was recordedfollowed by spider and mirid bug, whereas the lowest was the water bug (Table 3).Considering all growth stages, green leaf hopper population was the highest andstem borer was the lowest. The highest population of natural enemy (spider) wasrecorded followed by damselfly. From the Table 3 it may be concluded that thenumber of insect pest species was minimum as compared to natural enemies. Itmight be due to least or no use of chemical pesticides in farmers' field wheresurvey program was carried out. Pest populations were controlled naturally bytheir associated natural biocontrol agents.

Relationship between insect pests and their natural enemies: Relationshipbetween the number of insect pests and natural enemies in respect of three growthstages of rice is presented in figure 1 (A-C). At mid tillering stage, significantpositive relatinship was observed and it was expressed by 0.25%. At maximumtillering stage, relationship was positive but very much low. At panicle initiationstage, negative relationship was observed (Figure 1. A-C).

Population of insect pests and their natural enemies in different varieties ofT.Aman rice: Population of insect pests and their natural enemies among differentrice varieties during aman season is presented in Table 4. Significantly the highestpopulation of short horned grasshopper was recorded in rice Accession No. 20followed by HYV of rice and the lowest was in Chinigura aromatic rice. The longhorned grasshopper was also the highest in Accession No 20. Green riceleafhopper population was maximum in HYV of rice followed by Chinigura, localmota and Accession No.20. Among natural enemies, Chinigura rice harbored thehighest number of spider population followed by Accession No.20, HYV of riceand Local mota. Accession No. 20 had the highest damselfly population which wasstatistically similar to that of local mota and Moulata rice followed by Chiniguraaromatic rice. Ichneumonid wasp population did not differ significantly amongrice cultivars during aman season (Table 4).

M. M. H. KHAN

98

C

Fig. 1.(A-C). Relationship between insect pests and their natural enemies at early tillering,maximum tillering and panicle stages of rice plant

B

A

Table 4. Pest population and their natural enemies in different varieties of T.Amanrice grown in PSTU farm

Variety Pest population /10 Population of natural complete sweep enemies/10 complete sweep

SHGH LHGH GLH Spider Damselfly IchneumonidLalmota 7c 0c 8b 3b 4a 2Moulata 6c 0c 0c 1c 4a 1Chinigura 2d 2b 9b 6a 3ab 0HYV rice 11b 2b 12a 3b 2b 0Accession No. 20 37a 6a 7b 4b 5a 2Level of significance - - - - - NS

In a column means accompanied by the same letter(s) are not significantly different at 5 % levelby DMRT.

Population of insect pests at four locations of Patuakhali district: Among thehigh incidence of insect pests, the population of short horned grasshopper andgreen rice leafhoppers was the maximum at all four locations indicating thehighest occurrence at Patuakhali sader followed by Mirjagong and Bauphal, andlowest was at Dumki. Long horned grasshoppers and others were lower at all 4locations showing the lowest incidence at Dumki (Figure 2).

Population of natural enemies at four locations of Patuakhali district: Among4 natural enemies, the population of spider and damselfly was the maximum atBauphal as compared to other 3 locations. However, ground beetle was notobserved at Bauphal. At Dumki, similar trend was also observed in the number ofspider and damselfly population but the lowest was Ichneumonid wasp. Groundbeetle population was the maximum at Dumki among 4 locations. At Mirjagong,the population of damselfly and spider was more or less similar, while the lowestpopulation was observed in case of ground beetle followed by ichneumonid. AtPatuakhali sader, the maximum number damselfly of population was observedfollowed by spider and ichneumonid while the lowest population of ground beetlewas evident (Figure 3).

Diversity of insect pests and natural enemies as influenced by different habitatsDiversity indices of insect pests were varied at different rice habitats. Both


99

diversity index (H) and evenness (J) showed higher values in rice-banana habitat(1.02 and 0.87, respectively), followed by rice-vegetable habitat (0.99 and 0.85,respectively) while rice-rice monoculture showed lower diversity (0.96) andevenness (0.82) (Table 5). Richness index was found highest in rice-banana (4.69)and lowest in rice-rice habitat (4.34). On the other hand, the values of D(reciprocal form of Berger Parker's Dominance Index) showed highest in rice -banana (5.27) followed by rice-homestead (4.95) and lowest in rice-vegetable(4.71) indicating the highest diversity was in rice-banana and lowest in rice-vegetable habitat (Table 5).

M. M. H. KHAN

100

Figure 2. Number of insect pests observed in aman rice field at four locations of Patuakhalidistrict

Figure 3. Number of important natural enemies at four locations of Patuakhali district

Table 5. Diversity indices of insect pests and natural enemies in aman season

Habitats Diversity index (H) Evenness (J) Richness (M.I.) DInsect PestsRice-banana 1.02 0.87 4.69 5.27Rice-homestead 0.97 0.83 4.36 4.95Rice-vegetable 0.99 0.85 4.44 4.71Rice-rice 0.96 0.82 4.34 4.92

Natural EnemiesRice-banana 0.79 0.79 2.75 3.37Rice-homestead 0.74 0.74 2.73 2.28Rice-vegetable 0.76 0.76 2.81 2.48Rice-rice 0.73 0.72 2.79 2.19

Diversity indices of natural enemies also varied at different rice habitats. Rice-banana habitat showed the highest values for diversity index (0.79) and evenness(0.79); and rice-rice habitat showed the lowest values for diversity index (0.73)and evenness (0.72). Richness index was found highest in rice-vegetable (2.81)followed by rice-rice habitat (2.79) while the lowest richness index was in rice-homestead habitat (Table 5). On the other hand, the values of D showed highest inrice-banana (3.37) followed by rice-vegetable (2.48) and lowest in rice-rice (2.19)habitat indicating the highest diversity was in rice-banana and lowest in rice-ricehabitat (Table 5).

Nath & Bhagabati (2002) reported that the leafhopper population was firstappeared in the rice seedbed during June-July, reaching the peak in October-November in the main rice field. Lanjar et al. (2002) found that maximumnymphal activity of grasshopper species was noticed during three weeks aftertransplanting of crop and adults were most active at crop maturity. Miura et al.(1990) estimated relative and absolute density of damselfly populations in ricefields and found that nymphal population peaks appeared during June and August.Wang et al. (2001) reported that the spatial distribution of mixed spiderpopulations in rice fields was different during different developmental stages ofrice. Anbalagan and Narayanasamy (1999) found that population abundance andspecies diversity of the spiders were directly related to the growth stages of riceplant. There was a clear difference in the occurrence of spider species in different


101

regions of the rice ecosystem. Hu et al. (1998) reported that flooded fields inwhich no insecticides were applied had high numbers of carabids and spiders.

The results revealed that diversity of insect pests and natural enemies werevaried according to adjacent habitats. In a study, Hurlbert et al. (1989) also foundthat the diversity of arthropod communities in paddy fields were distinctlydifferent according to habitat, type of field and growth stage of rice. In the presentstudy, the results revealed that in most cases, the diversity indices for both insectpests and natural enemies were lowest in rice-rice habitat (monoculture) comparedto other polyculture habitats.

Several authors have concluded that the abundance and diversity of predatorsand parasitoids within a field are closely related to the nature of the vegetationsurrounding the field (Andow 1991, Hopper 1989). There is wide acceptance ofthe importance of vegetation surrounding the field margin which act as thereservoirs of the natural enemies of crop pests.

Interestingly, it was found that the incidence of stem borer, rice bug and othermajor insect pests in aman season was low compared to short horned grasshoppersand green leafhoppers. Main reasons for low population might be due to perchingprovided by most of the farmers to encourage insect predatory birds in reducingpest population and growing of traditional local variety viz., Lalmota in Barisalarea in T. aman rice.

From the present study it may be concluded that among natural enemies, thepredaceous insect damselfly and spiders were more abundant in rice fields.Therefore, it might be possible to conserve the natural enemies of insect pests andeventually to enhance the natural biological control of insect pests by cultivatingrice and without applying insecticides in coastal rice agro ecosystem and also bycultivating rice adjacent to banana field (rice-banana habitat).

REFERENCES

ANBALAGAM, G. & NARAYANASAMY, P. 1999. Population fluctuation ofspiders in the rice ecosystem of Tamil Nadu. Entomol. 24(1): 91-95.

ANDOW, D.A. 1991. Vegetational diversity and arthropod population response.Annu. Rev. Entomol. 36: 561-586.

CHIU, S.C. 1979. Biological control of the brown planthopper. In: Brownplanthopper threat to rice production in Asia. Manila (Philippines): Internat.Rice Res. Inst. p335-355.

M. M. H. KHAN

102

DELONG, T.M. 1975. A comparison of three diversity indices based on theircomponents of richness and evenness. Oikos. 26(2): 222-227.

HAGEN, K.S. & HALE, R. 1974. Increasing natural enemies through use ofsupplementary feeding and non-target prey. Proceedings of the summerInstitute for Biological Control of Plant Insects and Diseases (Jackson:Mississipi Univ. Press), 674p.

HEINRICHS, E.A. 1994 (ed.) Biology and management of rice insects. WileyEastern Ltd., pp. 779.

HOPPER, K.R. 1989. Conservation and augmentation of Microplitis croceipes forcontrolling Heliothis spp. Southwest. Entomol. Suppl. 12: 95-115.

HU, D.X., YU, Z.R., HAN, C.R., HE, J.H. & PAOLETTI, M.G. 1998. Communitystructure of carabids and spiders in agriculture landscape in Qian Jiang,Hubei Province. Acta Entomological Sinica. Supplement. 41: 91-97.

HURLBERT, S.H., SHANNON-WIENNER, E.C. PIELOU, YOU, M. S. and WU,Z. F. 1989. The diversity of arthropod communities in paddy fields. J.Fujuan Agril. College. 18(4): 532-538.

LANJAR, A.G., TALPUR, M.A., KHUHRO, R.D. & QURESHI, K.H. 2002.Occurrence and abundance of grasshopper species on rice. Pakistan J.Applied Sci. 2(7): 763-767.

LITSINGER, J.A. 1989. Second generation insect pest problems on high yieldingrices. Tropical pest management. 35(3): 235-242.

MARGALEF, R. 1958. Information theory in ecology. Gen. Sys. 3: 36-71.MENZIES, R.L., GEORGE, R.Y. & ROWE, G.T. 1973. Adyssal environment and

ecology of the world oceans. John Wiley and Sons, New York. 488p.MIURA, T., TAKAHASHI, R.M. & STEWART, R.J. 1990. Estimation of absolute

numbers damselfly nymphs (Odonata: Coenagrionidae) by dipper samplingin California rice fields with seasonal, spatial distributions and vegetationassociation. J. Amer. Mosquito Cont. Assoc. 6(3): 490-495.

NATH, P & BHAGABATI, K.N. 2002. Population dynamics of leafhopper vectorsof rice tungro virus in Assam. Indian Phytopathology. 55(1): 92-94.

PIELOU, E.C. 1966. The measurement of diversity in different types of biologicalcollections. J. Theor. Biol. 13: 131-144.


103

SHANNON, C.E. & WEAVER, W. 1963. The mathematical theory ofcommunication. Univ. Press, Urbane. pp. 117.

SIDDIQUE, A K M T. 1992. An overview of the ETL of rice pests and IPM scopein the content of rice production. In Proc. of the workshop on experiencewith modern rice cultivation in Bangladesh. BRRI, Gazipur, pp. 33-45.

SOUTHWOOD, T.R.E. 1978. Ecological Methods with particular reference to thestudy of insect populations. Chapman and Hall, London, pp. 524.

WAHIDUZZAMAN, M. 1993. Studies of the insect predatory behavior of theblackdrongo in rice ecosystem. M. S. Thesis, Institute of Post graduateStudies in Agriculture, Gazipur. 59p.

WANG, Z., YAN, H.M. & WANG, H.Q. 2001. Studies on the dynamics of spatialdistribution of mixed spider populations in rice fields. Plant Protection.27(6): 9-11.

WAY, M.J. & HEONG, K.L. 1994. The role of biodiversity in the dynamics andmanagement of insect pests of tropical irrigated rice-a review. Bull. Ent. Res.86: 567-587.

XIAOPING, Y., HEONG, K.L., CUI, H. and BARRION, A.T. 1995. Role of non-rice habitats for conserving egg parasitoids of rice planthoppers andleafhoppers. In: Hokyo N. Norton G, editors. Proceedings of theInternational Workshop on Pest Management Strategies in Asian MonsoonAgroecosystem (Kumamoto 1995). 63-77p.


M. M. H. KHAN

104

105

Scientific Note

EFFECT OF VITAMIN-SUPPLEMENTATION ON THE SILKWORM,BOMBYX MORI L.

MD. KAMRUL AHSAN, ATAUR RAHMAN KHAN & TASNIMA FERDOUS

Department of Zoology, Rajshahi University, Rajshahi-6205, Bangladesh

The effect of supplementation of mulberry leaves (Morus alba L.) with vitamin-B and vitamin-C at different concentrations (29.87+333.33, 61.57+333.33,95.29+333.33, 131.22+333.33, 29.87+142.86, 61.57+142.86, 95.29+142.86,131.22+142.86, 29.87+ 66.67, 61.57+66.67, 95.29+66.67, 131.22+66.67,29.87+32.26, 61.57+32.26, 95.29+32.26 and 131.22+32.26 µg/ml) of vitamin Band C, respectively on some important economic parameters of the multivoltinesilkworm, Bombyx mori L. (variety-BSR-95/14(M)) was assessed. The cocooncharacters e.g. cocoon length and weight, shell weight, shell ratio and shell indexwere significantly increased at moderate vitamin concentrations viz., 95.29µg/ml of vitamin B and 66.67 µg/ml and 142.86 µg/ml of vitamin C. It wasobserved that the development of cocoon takes place upto a particular dose(95.29+142.86 µg/ml) of B and C. The reproductive potential was significantlyincreased in the treated insects except at higher concentrations. Vitaminsproduced higher mortalities at higher concentrations e.g. 29.87+333.33,95.29+333.33, 131.22+333.33, 29.87+142.86, 131.22+66.67, 29.87+32.26,95.29+32.26 and 131.22+32.26 µg/ml vitamin B and C, respectively. There wasno significant effect of vitamin supplementation on the sex ratio in B. mori.. Keywords: Vitamin, supplementation, B. mori, economic characters.

Silkworms are well known industrial insects which produce natural silk.Because of economic importance of silk yarn, the main objective of silkwormrearing is the progressive improvement of economic traits to produce quantity andquality silk. Feeding of nutritionally enriched leaves showed better growth anddevelopment of silkworms as well as gain in economic characters of cocoons(Krishnaswami et al. 1971). Vishwanath & Krishnamurthy (1983) studiedinfluence of micronutrients on larval development and cocoon characters ofsilkworm. Fortification of mulberry leaves with supplementary compounds toincrease the larval growth and development of B. mori has been carried out bymany researchers. These include vitamins (Saha & Khan 1996, Nirwani &


*Corresponding Author: [email protected]

Kaliwal 1996, Nirwani et al. 1998, Khan & Saha 2003, Etebari et al. 2004,Rahmathulla et al. 2007), hormones (Magadum et al. 1992, Trivedy et al. 1993,Saha & khan 1997), amino acid (Khan & Faruki 1990, Qadar et al. 1994, Saha etal. 1994) and minerals (Magadum et al. 1992, Islam & Khan 1993, Saha & Khan1996). Nutritional background of the larval stage significantly influences the statusof the resulting larva, pupa and fibre (Ahmed et al. 1998, Rahmathulla et al. 2002,Khan & Saha 2003, Etebari & Matindoost 2004). Although the mulberry leavesconstitute a complete diet for the mulberry silkworm, nutritional deficiencies mayoccur due to different reasons.

Dosages of vitamins are very determinative for normal growth of silkworm.Etebari et al. (2004) reported that the yield decreases when ascorbic acidconcentration is enhanced in silkworm diet. Similar effects from multivitaminshave been confirmed by Saha & Khan (1996) and Etebari & Matindoost (2004).The effects of vitamin B and C supplementations on yield and other importantparameters of the silkworm have been reported in this investigation.

The eggs of silkworm variety BSR 95/14(M) were obtained from theGermplasm Bank, Bangladesh Sericulture Research and Training Institute,Rajshahi and reared in the Sericulture Laboratory, Department of Zoology,University of Rajshahi, following the silkworm rearing techniques (Krishnaswami1978, Rahman 1983). After disinfection and incubation of the eggs neonate larvaewere reared up to the second instar on fresh mulberry leaves (Morus alba L.).Third instar larvae were divided into 17 experimental groups including the control.Each group consisted of three replications, each of 60 larvae. The rearing ofsilkworm was conducted at room temperature and relative humidity. Thetemperature and humidity were measured four times daily by thermohygrometerthroughout the rearing period. The average temperature and humidity were 28 ±2°C and 75±6%, respectively.

Four different concentrations of Vitamin B (Opsovit®) viz. 29.87, 61.57, 95.29and 131.22 µg/ml as well as four different concentrations of vitamin C (Ceevit),Bangladesh 32.26, 66.67, 142.86 and 333.33 µg/ml were prepared by mixing therequisite amounts of the vitamins in distilled water. Then different concentrationsof vitamin B and C were used combinedly at sixteen possible combinations. Thetreatments were as follows: T0 = Control, T1 = 29.87+333.33, T2 = 61.57+333.33,T3 = 95.29+333.33, T4 = 131.22+333.33, T5 = 29.87+142.86, T6 = 61.57+142.86,T7 = 95.29+142.86, T8 = 131.22+142.86, T9 = 29.87+ 66.67, T10 = 61.57+66.67,


106

T11 = 95.29+66.67, T12 = 131.22+66.67, T13 = 29.87+32.26, T14 = 61.57+32.26,T15 = 95.29+32.26 and T16 = 131.22+32.26 (µg/ml). Fresh, whole mulberry leaveswere treated by dipping in these solutions and then dried by fanning. The treatedleaves were fed to the larvae from 3rd to 5th instars, once a day. Control insectswere reared on mulberry leaves dipped in distilled water only. Approximately onekilogram of mulberry leaves was supplied for each replication.

After harvesting cocoons, the pupae were sexed and counted carefully. Thecocoon weight and length, shell weight and shell ratio were then recorded formales and females separately. The moths of the opposite sexes from variousconcentrations were allowed to mate and the mated females were observed foroviposition. Eggs were collected after 6 hours mating of the female moths andretained for recording their fertility. Mortality at various developmental stages wasalso noted.

Data of all the characters were subjected to analyses of variance. The sex ratiowas analyzed following Zar (1974). The shell and ovipositional indices werecomputed following Joshi (1985) and Desmukh et al. (1977), respectively. Thepercent reproductive control (PRC) was computed following Rizvi et al. (1980).The standardized normal deviate values (d-values) were calculated by standardformula. The mortality data were corrected by Abbott's formula (Abbott 1925).

The cocoon characters like cocoon length (tip to tip) and weight (cocoon shell+ pupa), shell weight (cocoon wt. - pupal wt.), and shell ratio were significantlyincreased when the larvae were reared on mulberry leaves enriched with vitaminB and C in some treatments. The highest cocoon length and weight were observedat 95.29+142.86 µg/ml of B and C in both the sexes. The highest shell weight andshell ratio were also observed at 95.29+142.86 µg/ml of B and C for males but forfemales these were at 131.22+142.86 µg/ml and 29.87+ 66.67 µg/ml of B and Crespectively. In these dose combinations moderate percentage e.g. 95.29 and131.22 µg/ml of vitamin B and 66.67 and 142.86 µg/ml of vitamin C were used.Many researchers found that the cocoon characters of B. mori were improved bydifferent nutrients such as ascorbic acid, folic acid, thiamin, vitamin B complex,etc. ( Saha & Khan 1996, Nirwani & Kaliwal 1996, Khan & Saha 2003, El-Karaksy & Idris 2009). Etebari & Matindoost (2004) reported that cocoonparameters were enhanced by multivitamin supplementation but the shell ratio wasreduced. At the higher concentrations of vitamin B or C in silkworm diet, thecocoon characters under study were considerably decreased. Saha & Khan (1996)also obtained similar results.

Effect of vitamin-supplementation on Bombyx mori L.

107

Table 1. Effect of vitamins on the cocoon characters of B. mori

Concentration Mean SD(µg/ml) Cocoon Cocoon Shell Shell Shell of Vitamin (%) Weight (g) Length(mm) Weight(g) Ratio indexT0 (control) 1.36 ± 0.042 44.78 ± 1.052 0.180 ± 0.008 9.96

a(1.66 ± 0.035) (47.19 ± 0.921) (0.176 ± 0.007) (6.85)T1= 29.87+333.33 1.34 ± 0.036 42.09 ± 1.162 0.182 ± 0.008 14.99 0.99

(1.65 ± 0.051) (48.62 3.138) (0.165 ± 0.006) (3.94) (0.99)T2 = 61.57+333.33 1.35 ± 0.031 44.27 ± 1.386 0.191 ± 0.007 7.60 0.99

(1.55 ± 0.093) (48.09 1.150) (0.175 ± 0.011) (7.43) (0.93)T3= 95.29+333.33 1.37 ± 0.064 44.32 ± 2.601 0.196 ± 0.007 13.85 1.01

(1.58 ± 0.064) (47.93 2.236) (0.181 ± 0.007) (3.16) (0.95)T4= 131.22+333.33 1.38 ± 0.026 44.46 ± 0.893 0.201 ± 0.012 14.96 1.01

(1.58 ± 0.053) (48.62 0.871) (0.184 ± 0.005) (3.32) (0.95)T5= 29.87+142.86 1.41 ± 0.035 45.71 ± 0.657 0.217 ± 0.009 11.59 1.04

(1.63 ± 0.031) (47.71 0.657) (0.189 ± 0.007) (3.47) (0.98)T6= 61.57+142.86 1.42 ± 0.035 47.19 ± 0.734 0.216 ± 0.009 13.71 1.04

(1.68 ± 0.031) (47.95 1.462) (0.202 ± 0.016) (6.91) (1.01)T7= 95.29+142.86 1.46 ± 0.025 48.18 ± 0.765 0.224 ± 0.010 16.34 1.07

(1.82 ± 0.076) (51.01 ± 2.712) (0.205 ± 0.005) (9.83) (1.10)T8= 131.22+142.86 1.45 ± 0.025 47.12 ± 0.326 0.231 ± 0.011 13.23 1.07

(1.75 ± 0.053) (49.48 0.592) (0.202 ± 0.007) (5.87) (1.05)T9= 29.87+ 66.67 1.40 ± 0.010 47.85 ± 0.760 0.230 ± 0.011 18.09 1.03

(1.64 ± 0.091) (51.19 ± 1.410) (0.192 ± 0.010) (6.55) (0.99)T10= 61.57+66.67 1.40 ± 0.010 47.19 ± 1.014 0.223 ± 0.021 15.95 1.03

(1.67 ± 0.031) (49.52 1.551) (0.186 ± 0.011) (8.34) (1.01)T11 = 95.29+66.67 1.39 ± 0.020 46.38 ± 1.284 0.206 ± 0.013 17.06 1.02

(1.69 ± 0.026) (50.81 ± 0.786) (0.180 ± 0.010) (4.73) (1.02)T12 = 131.22+66.67 1.38 ± 0.025 45.20 ± 0.956 0.181 ± 0.010 13.88 1.01

(1.65 ± 0.035) (46.53 0.577) (0.167 ± 0.006) (4.01) (0.99)T13 = 29.87+32.26 1.35 ± 0.015 47.05 ± 1.574 0.192 ± 0.010 11.31 0.99

(1.64 ± 0.068) (49.05 1.574) (0.161 ± 0.009) (7.46) (0.99)T14= 61.57+32.26 1.40 ± 0.000 46.96 ± 1.697 0.176 ± 0.011 14.76 1.03

(1.64 ± 0.074) (48.44 0.985) (0.160 ± 0.011) (4.80) (0.99)T15= 95.29+32.26 1.39 ± 0.021 46.24 ± 0.696 0.174 ± 0.012 15.13 1.02

(1.68 ± 0.050) (48.53 0.410) (0.175 ± 0.010) (11.87) (1.01)T16= 131.22+32.26 1.33 ± 0.010 47.29 ± 1.403 0.182 ± 0.007 9.52 0.98

(1.62 ± 0.015) (47.57 2.290) (0.159 ± 0.021) (9.28) (0.98)F-ratio 4.687** 5.056** 10.894** 4.846**

(3.576**) (2.081*) (6.213**) (1.990)aCorresponding means in females are in parentheses; * and ** significant at 5% and 1%, respectively.


108

The effect of vitamin supplementation on fecundity and fertility of B. mori isshown in Table 2. The fecundity and fertility of B. mori due to vitamins at variousconcentrations were significantly increased. Khan & Saha (2003) also observedthat thiamine supplementation had significant effects on fecundity and fertility ofB. mori.

The sex ratios of B. mori, resulting from various concentrations of vitaminshave been presented in Table 3. There was no significant effect of vitaminsupplementation on sex ratios of B. mori.

Table 2. Effect of vitamins on the reproductive potential of B. mori

Concentration (µµg/ml) Fecundity P.R.C Fertility (%) Ovipositionof Vitamin (%) (aMean + SD) (aMean ) indexT0 (control) 460.00 ± 16.523 88.04 T1 459.33 ± 3.512 0.15 87.35 1.00T2 449.33 ± 19.553 2.32 91.02 0.98T3 457.67 ± 4.509 0.51 91.27 0.99T4 462.67 ± 15.308 -0.58 91.52 1.01T5 481.33 ± 8.327 -4.64 93.41 1.05T6 485.67 ± 7.024 -5.58 94.14 1.06T7 491.33 ± 5.132 -6.81 95.23 1.07T8 488.00 ± 9.644 -6.09 94.72 1.06T9 472.00 ± 1.000 -2.61 93.93 1.03T10 457.33 ± 7.572 0.58 93.43 0.99T11 453.33 ± 13.317 1.45 93.98 0.99T12 452.33 ± 4.619 1.67 93.88 0.98T13 444.67 ± 6.506 3.39 92.38 0.97T14 436.67 ± 11.015 1.80 89.81 0.95T15 425.33 ± 8.737 2.60 87.03 0.92T16 413.00 ± 13.000 2.90 85.64 0.90F-ratio 13.789** 13.926**

aMeans of 30 female's egg; P.R.C indicates the percent reproductive control; * and ** significantat 5% and 1%, respectively. T1 - T16 as in Table 1.

Effect of vitamin-supplementation on Bombyx mori L

109


110

Table 3. Effect of vitamins on the sex-ratio(%) of B. mori

Concentration (µg/ml) No. of No. of No. of No. of Males Females χ²-of Vitamin (%) larvae pupae obtained Males Females (%) (%) value

T0 (control) 190 175 73 102 41.71 58.26 4.81

T1 190 182 80 102 43.96 56.04 2.66

T2 190 172 95 77 55.23 44.77 1.88

T3 190 180 98 82 54.44 45.56 1.42

T4 190 180 80 100 44.44 55.56 2.22

T5 190 185 105 80 56.76 43.24 3.38

T6 190 176 90 86 51.13 48.86 0.09

T7 190 174 95 79 54.60 46.40 1.47

T8 190 172 77 95 44.77 55.23 1.88

T9 190 172 77 95 44.77 55.23 1.88

T10 190 178 86 92 48.31 51.69 0.20

T11 190 183 93 90 50.90 49.18 0.05

T12 190 185 82 102 44.86 55.13 1.95

T13 190 185 80 105 43.24 56.58 3.38

T14 190 178 86 92 48.31 51.69 0.20

T15 190 180 92 88 51.11 48.89 0.09

T16 190 180 88 92 48.89 51.11 0.09

T1 - T16 as in Table 1.

The results of the supplementation of vitamins on mortality obtained in thepresent experiments are presented in Table 4. It was observed that vitaminsupplementation slightly reduced the larval and pupal mortalities in B. mori atsome concentrations as compared to the controls. Khan & Saha (1996) observedthat at higher concentrations citric acid produced significantly higher mortalitiesin B. mori. Although in 95.29+333.33, 131.22+333.33 and 29.87+142.86 µg/mldoses showed significant mortality having higher concentrations of vitamin B, the

dose 95.29+333.33 µg/ml produced increased cocoon characters. The insectssurviving treatments are expected to have better growth and development ascompared to their dead counterparts.

The data clearly show that the effect of vitamins enhances the economicsparameters of silkworm at moderate concentrations.

Table 4. Effect of vitamins on the mortality (%) of the developmental stages ofB. mori

Concentration (µg/ml) Mortality (%) Corrected *d-value Level of of vitamin (%) Larvae Pupae Total mortality significanceT0 (control) 5.263 2.778 8.041 -- -- --

T1 2.631 1.622 4.253 -4.119 1.541 P<0.05

T2 6.315 3.371 9.686 1.789 -0.564 NS

T3 2.631 2.703 5.334 -2.943 1.058 P<0.05

T4 3.158 2.174 5.332 -2.946 1.059 P<0.05

T5 4.000 0.538 4.538 -3.809 1.410 P<0.05

T6 5.263 2.222 7.485 -0.605 0.202 NS

T7 6.315 2.247 8.562 .567 -0.184 NS

T8 5.263 4.444 9.707 1.812 -0.571 NS

T9 5.263 4.444 9.707 1.812 -0.571 NS

T10 4.211 2.198 6.409 -1.775 0.615 NS

T11 4.000 1.613 5.613 -2.640 0.939 NS

T12 1.052 1.598 3.196 -5.267 2.062 P<0.05

T13 1.052 1.598 2.650 -5.862 2.353 P<0.05

T14 4.211 2.198 6.409 -1.775 0.615 NS

T15 2.631 2.703 5.334 -2.944 1.058 P<0.05

T16 2.631 2.703 5.334 -2.944 1.058 P<0.05

Note: *d = Standardized normal deviate. T1 - T16 as in Table 1.


111

REFERENCESABBOTT, W. S. 1925. A method of computing the effectiveness of an insecticide.

J. Econ. Entomol. 18: 265-267.AHMED, C.A.A., CHANDRAKALA, M.V., SHIVAKUMAR, C. &

RAGHURAMAN, R. 1998. Food and water utilization patterns underrestricted feeding durations in Bombyx mori of pure Mysore race. J. Exp.Zool. India 1: 29-34.

DESMUKH, P. D., RATHORE, Y. S. & BHATTACHARYA, A. K. 1977. Studieson growth and development of Diacrisia oblique (Lep: Arctiidae) on sixteenplant species. Z. angew. Ent. 84: 431-435.

EL-KARAKSY, I.A. & IDRIS, M. 2009. Ascorbic acid enhances the silk yield ofthe mulberry silkworm, Bombyx mori. J. Appl. Entomol. 109: 81-86.

ETEBARI, K. & MATINDOOST, L. 2004. Effects of hypervitaminosis of vitaminB on silkworm biology. J. bio-sci. 29 : 417-422.

ETEBARI, K., EBADI, R. & MATINDOOST, L. 2004. Effect of feedingmulberry's enriched leaves with ascorbic acid on some biological,biochemical and economical characteristics of silkworm Bombyx mori.L.Int. J. Indus. Entomol. 8 : 81-87.

ISLAM, Z. & KHAN, A.R. 1993. Growth and development of the mulberrysilkworm, Bombyx mori L. (Lepidoptera, Bombycidae) of feedsupplemented with manganese sulphate. J. bio-sci. 1 : 21-30.

JOSHI, R.L. 1985. Studies on growth index for Eri silkmoth, Philosamia riciniHutt. (Lepidoptera: Saturniidae). Sericologia 25: 313-319.

KHAN, A. R. & SAHA, B.N. 2003. Nutritive effects of thiamine on the silkworm. Bombyx mori L. Bangladesh J. Zool. 31(2): 169-176.

KHAN, A.R. & FARUKI, S.I. 1990. Growth and development of Bombyx mori L.on feed supplemented with Para-Amino Benzoic Acid. Univ. J. Zool.Rajshahi Univ. 9 : 47-53.

KHAN, A.R. & SAHA, B.N. 1996. Nutritive effects of citric acid on the mulberrysilkworm . Bombyx mori L. Bull. Seric. Res. 7: 65-69.

KRISHNASWAMI, S. 1978. New Technology of silkworm rearing. Central SilkBoard, India. 23pp


112

KRISHNASWAMI, S., KURNARARAJ, S.S., IJAYARAGLIAVAN, K. &KASTVISWANATHAN, K. 1971. Silkworm feeding traits for evaluatingthe quality of mulberry as influenced by variety, spacing and nitrogenfertilization. Indian J. Seric. 10(1) : 79-90.

MAGADUM, S.B., HOOLI, M.A. & MAGADUM, V.B. 1992. Effect ofapplication of juvenile hormone analogue in IV instar followed by thyroxinein the pure Mysore breed of Bombyx mori. (L.) Sericologia. 32(3) : 385-390.

NIRWANI, R.B. & KALIWAL, B.B. 1996. Effect of Folic acid on economic traitsand the change of some metabolic substances of bivoltine silkworm, Bombyxmori L. Korean J. Seric. Sci. 38 : 118-123.

NIRWANI, R.B., HUGAR, I.I. & KALIWAL, B.B. 1998. Supplementation ofriboflavin on economic parameters and biochemical changes of thesilkworm, Bombyx mori L. Bull. Seric. Res. 9: 37-41.

QADER, M.A., HAQUE, R. & ABSAR, N. 1994 Amino acid contents in posteriorsilk gland of Bombyx mori. (Bombycidae : Lepidoptera) influenced byquality of mulberry leaves. Bull. Seric. Res. 5 : 63-68.

RAHMAN, S.M. 1983. Technology of mulberry silkworm rearing suitable for theclimatic condition in Bangladesh. Reshom 1,71-79.

RAHMATHULLA, V.K., DAS, P., RAMESH, M. & RAJAN, R.K. 2007. Growth ratepattern and economic traits of silkworm, Bombyx mori. L. under the influenceof folic acid administration. J. Appl. Sci. Environ. Manage. 11(4): 81-84.

RAHMATHULLA, V.K., SURESH, H.M., MATHUR, V.B. & GEETHADEVI2002. Feed conversion efficiency of Elite bivoltine CSR hybrids silkworm,Bombyx mori. L. reared under different environmental conditions.Sericologia. 42: 197-203.

RIZVI, S. J. H., PANDEY, S.K., MUKERJI, D. & MATHUR, S. N. 1980. 1.3.7-Tri-methylxanthine, a new chemosterilant for stored grain pest,Callosobruchus chinensis L. Z. angew. Ent. 90: 378-381.

SAHA B.N. & KHAN, A.R. 1996. Effect of dietary supplementation of vitaminsand minerals on the growth and development of Bombyx mori L. Bangladesh.J. Zool. 24(2) : 125-131.

SAHA B.N. & KHAN, A.R. 1997. The nutritive effects of Sinafort(R) -B onBombyx mori L. Entomon 22(1) : 29-34.


113

SAHA, A. K., RAHMAN, M. S., SAHA, B. N. & UDDIN, M. 1994. Effect ofproline and leucine on the growth and development of silkworm, Bombyxmori L. Univ. J. Zool. Rajshahi Univ. 13 : 75-79.

TRIVEDY, K., REMADEVI, O.K., MAGADUM, S.B. & DATTA, R.K. 1993.Effect of Juvenile hormone analogue, Labomin on the growth and economiccharacters of silkworm, Bombyx mori L. Indian J. Seric. 32(2) : 162-168.

VISHWANATH, A.P. & KRISHNAMURTHY, K. 1983 . Effect of foliar spray onthe larval development and cocoon characters of silkworm (Bombyx moriL.). Indian .J. Seric. 11/12 : 1 -6.

Zar, J. H. 1974. Bio-statistical Analysis. Prentice Hall Inc., USA. 620 pp.



114

Documents

BANGLADESH ENTOMOLOGICAL SOCIETY - …bdentsoc.org/wp-content/uploads/2015/02/BJE-23-1.pdf · BANGLADESH ENTOMOLOGICAL SOCIETY ... Taxonomic description should be given in telegraphic