Sarhad J. Agric. Vol.28, No.2, 2012

FEEDING POTENTIAL OF LADY BIRD BEETLE, BRUMUS SUTURALIS FABRICIUS (COLEOPTERA: COCCINELLIDAE) ON COTTON MEALY BUG PHENACOCCUS

SOLENOPSIS (TINSLEY) IN LABORATORY AND FIELD

SHAH NAWAZ KHUHRO*., MOHAMMAD KHAN LOHAR**, GHULAM HUSSSAIN ABRO**, MUZAFFAR ALI TALPUR***, and RABDINO KHUHRO**

* Entomology Section, Central Cotton Research Institute, Sakrand, Sindh – Pakistan. ** Department of Entomology, Sindh Agriculture University, Tandojam – Pakistan. *** Department of Plant Protection, Sindh Agricuture University, Tandojam – Pakistan.

E-mail: snkhuhro@hotmail.com

ABSTRACT

An experiment was conducted to determine the feeding potential of lady bird beetle, Brumus suturalis (Fab.) on cotton Mealy bug, Phenacoccus solenopsis in the laboratory and field conditions in Department of Entomology, Sindh Agricultural University, Tandojam, Pakistan during July – August, 2007. The laboratory results revealed that B. suturalis was voracious feeder of Mealy bugs. The fourth instar devoured maximum mean number of Mealy bugs (55.11±1.38) /day/larva followed by third instar (32.51±1.09), second instar (32.5±0.08) and first instar (25.1±1.41) Mealy bug and the adults female devoured more number of Mealy bug (131.51±2.10) than male (129.57±314) per day under laboratory conditions (26+2oC). The field results showed that, fourth instar devoured more mean number of Mealy bugs / day / larva of (34.6±1.41), followed by third instar (25.0±0.63), second instar (23.7±0.47) and first instar (19.0±0.16) Mealy bug/larva/day) and the adults female devoured more mean number (72.03 ± 6.16) than male (69.9 ± 6.31) per day. The lower consumption rate in the field may be attributed to the additional time required by the predators in searching of prey.

Key Words: Feeding Potential, Ladybird beetle, Cotton Mealy bug, Laboratory, Development stage.

Citation: Khuhro, S.N., M.K. Lohar, G.H. Abro, M.A. Talpur and R. Khuhro. 2012. Feeding potential of lady bird beetle, brumus suturalis fabricius (Coleopteran: Coccinellidae) on cotton mealy bug phenococcus solenopsis (Tinsley) in laboratory and field. Sarhad J. Agric. 28(2):259-265

INTRODUCTION

The Cotton crop is attacked by both sucking and chewing type insects. The sucking type including, white fly, aphid, thrips, mealy bugs and mites and chewing type including, grass hopper, termite, weevils and lepidopteron insects. Among these mealy bug is the serious pest of cotton and has resulted in severe damage during the last few years (Solangi et al., 2008; Lohar and Khuhro, 2005).

A new mealy bug (P. solenopsis) appeared recently and has attained the status of a serious pest on a wide rang of host plants. It was recorded from 154 plant species including field crops, vegetables, ornamentals, weeds, bushes and trees. The economical loss was recorded on cotton, brinjal, okra, tomato, sesame, sunflower and China rose with plant death in severe conditions (Arif et al., 2002).

In Pakistan many species of Coccinellid predators, (Coleoptera: Coccinellidae) are very effective to control many insect-pests, particularly on small and soft body insects. According to Michaud, (2001), there are more than 4000 species of Coccinellids around the world. Among these common species in Sindh, Pakistan are 7-spotted beetle, Coccinella septempunctata (L), Transverse beetle, Coccinella transversalis, (F) 11-spotted beetle, Coccinella undecimpunctata (L), striped beetle, Brumus sutuaralis (F), Zigzag beetle, Menochilus sexmaculatus (F), 13- spotted beetle Hippodamia convergens, 9- spotted beetle, Hippodamia variegate, Scymnus spp, Stethorus punctum and many others are common predators of different sucking insect pests of several crops (Hashmi, 1994; Lohar, 2001).

The three-striped beetle, Brumus sutuaralis belonging to the Subfamily Coccinellinae, order Coleoptera is important and most voracious predator of mature and immature stages of mealy bug on different field and vegetable crops in Sindh, Pakistan (Lohar, 2001).

Keeping in view the above facts and importance of biological control of cotton mealy bug, the study on feeding potential of B. suturalis against cotton mealy bug in laboratory and field conditions was undertaken.

Shah Nawaz Khuhro et al. Feeding potential of lady bird beetle, on cotton mealy bug …

260

MATERIALS AND METHODS

Feeding Potential B. suturalis in Laboratory Conditions In order to study the feeding potential of lady bird beetle, B. suturalis the cotton mealy bug was collected

from different field crops surroundings the Tandojam and predator was reared in the laboratory at 25 ± 2°C. The feeding preference of larval instars and adults (male and female) on cotton Mealy bug was determined during their life period under laboratory conditions.

Feeding Potential of Larval Instars

After hatching from eggs, the first instars larvae of B. suturalis were transferred into petri dishes (9 cm dia.) with the help of camel hairbrush. For feeding potential, a single larva (per petri dish) was introduced with known number of mealy bug crawlers (on daily basis) along with the leaves of cotton crop from which the mealy bugs were collected and replicated five times. The Mealy bug consumption of each larval instars of predator was observed at 24 hrs intervals daily until the larvae entered into next developmental stage. The experiment was continued upto pupation. This was repeated in 1st, 2nd, 3rd and 4th instars larvae of the predator. The feeding longevity of instars was also recorded.

Feeding Potential of Adults

Newly emerged adults of lady bird beetle, B. suturalis (male and female) were kept separate in petri dishes and same experiment was repeated by providing known number of Mealy bug crawlers to both sexes of adult beetles. The consumption of Mealy bugs was recorded at 24 hrs intervals daily by counting the number of live Mealy bugs. The feeding longevity of adults was also recorded.

Feeding Potential of B. suturalis under Field Condition

Feeding Potential of Larval (grub) Instars

For assessing the field potential of predator in field of Plant Protection Faculty, Sindh Agriculture University, Tandojam, five cotton plants were planted in earthen pots and caged in the experimental field. After hatching from eggs, the first instar coccinellid larva was transferred into field cages by camel hairbrush in the cotton field. For feeding potential a single larva was assessed with known number of hosts along with the leaves of host crop on which the prey were collected and replicated five times. This was repeated in 1st, 2nd, 3rd and 4th instars larvae.

The hosts/prey consumption of each larval instars of each predator was observed after 24 hours daily until the larvae entered into next developmental stage. The experiment was continued upto pupation. The feeding longevity of instars was also recorded.

Feeding Potential of Adults

Newly emerged adults of predator were selected from pupal culture at random for feeding potential. The male and female adults were kept separate in field cages in cotton field and same experimental procedure like larvae was repeated by providing different density of hosts/prey to each adult beetle. The consumption of hosts/prey was recorded after 24 hrs daily by counting the number of live hosts/prey. The feeding longevity of adults was also recorded. The experiment was repeated five times. The statistical analysis of means and standard error was carried out by software Student Statistics 1.8.

RESULTS AND DISCUSSION

Feeding Rate and Development Period of B. suturalis Reared on Cotton Mealy Bug, Phenacoccus solenopsis in Laboratory

Feeding Potential of Larval Instars

The results (Fig.1) represent the comparative feeding rate and development period (days) of different larval (grub) instars and adults of B. suturalis reared on cotton Mealy bug, from August to September 2006 in laboratory at 26 ± 20C and R.H. 65 ± 5%. The feeding rate of larval instars increased with age and as they underwent successive moulting to the next instar. The results (Fig. 1) revealed that all larval instars of B. suturalis were voracious feeders, however the fourth instar devoured more number of Mealy bug / day / larva of (55.11±1.38) followed by third instar (32.51±1.09), second instar (32.5±0.08) and first instar (25.1±1.41 Mealy bug/larva/day). The statistical data show that 4th stage of B. suturalis consumed significantly (P<0.01) more mealy bugs than other larval stages. The results thus

Sarhad J. Agric. Vol.28, No.2, 2012

261

suggested that after the fourth stage the larvae entered into pupa stage at 11th day of larval life. The duration (days) of first, second, third and fourth instar larvae were 2.0, 2.0, 3.0 and 3.0 days, respectively on Mealy bug. The results agreed with Saikia and Balasubramanian, (2002) who found that grub period was prolonged when reared on nymphs of aphids as compared to Mealy bug nymphs. The Coccinellid grubs consumed a total of (239.60) mealy bugs during their first, second, third and fourth instars. The female beetle consumed significantly more mealy bug than the male.

The data in Fig. 2 further indicated the feeding rate of different larval instars. The first instar consumed (50.2±2.33) Mealy bug, second instar (65.0±2.03), third instar (97.53±3.41) and fourth instar (165.33±8.25) per stage/larva. The consumption rate of different larval instar indicates that fourth instar consumed significantly (P<0.01) more food as compared to other instars. The data agreed with Lohar and Khuhro, (2006) which Brumus suturalis fourth instar larvae devoured Mealy bugs/life/larva of (57.80), followed by third instar (40.0), second instar (31.6) and first instar (9.4). Earlier Ferran and Larroque, (1977) reported that the quantity of food consumed by predators depend on increase in larval size. As a consequence, the consumption per unit weight and proportion of food assimilated varied little between the instars. Khuhro et al. (2008) reported that the 3rd and 4th instars were more voracious as compare to 1st and 2nd instars.

Feeding Potential of Adults

The result in Fig. 1 further showed the feeding potential of adult male and female of B. suturalis on Mealy bug in laboratory under similar conditions. The data show that adult female consumed significantly (P<0.01) more mealy bugs (131.51±2.10 bug/day) than adult male (129.57±3.14) per day. The data in Fig.2 regarding the feeding rate of adults further indicate that the adult female consumed significantly (P<0.01) more mealy bugs (4076.81± 30.24 Mealy bugs/stage) than male adult (3887.1± 28.12 per stage). However, adult male of B. suturalis devoured (46.07 Mealy bugs per day) as compared to adult female (55.36) per day reported by Lohar and Khuhro (2006). However, Hodek and Honek (1996) reported that the amount of food consumed is strongly determined by predator size.

Longevity Period of Larvae and Adults

The results in Fig.3 suggested that after fourth instar the larvae entered in pupal stage at 13th day of larval life. The longevity (days) of first, second, third was non significant (3 days each) however, fourth instars lived for 4 days to transform into next life stage. The adult female lived significantly (P<0.01) more days (37) than the male (34) days on P. solenopsis in laboratory.

128

128.5

129

129.5

130

130.5

131

131.5

132

132.5

Ad.Male Ad.Female

Development Stages

Fee

ding

pot

enti

al/d

ay

P. solenopsis

0

10

20

30

40

50

60

70

L1 L2 L3 L4

Development Stages

Fee

ding

pot

enti

al/d

ay

P. solenopsis

Fig. 1. Feeding potential (per day) of larval and adult stages of B. suturalis on cotton Mealy bug in laboratory

Shah Nawaz Khuhro et al. Feeding potential of lady bird beetle, on cotton mealy bug …

262

3750

3800

3850

3900

3950

4000

4050

4100

4150

Ad.Male Ad.Female

Development Stages

Fee

ding

pot

enti

al/s

tage

P. solenopsis

0

20

40

60

80

100

120

140

160

180

200

L1 L2 L3 L4

Development Stages

Fee

ding

pot

enti

al/s

tage

P. solenopsis

Fig. 2. Feeding potential (per stage) of larval and adult stages of B. suturalis on cotton Mealy bug in Laboratory

0

10

20

30

40

50

60

Ad.Male Ad.Female

Development Stages

Lon

givi

ty o

f B

. sut

ural

is

P. solenopsis

00.5

11.5

22.5

33.5

44.5

5

L1 L2 L3 L4

Development Stages

Lon

givi

ty o

f B

. su

tura

lis

P. solenopsis

Fig. 3 Longevity of B. suturalis on P. solenopsis in laboratory

Feeding Rate of B. suturalis Reared on Cotton Mealy Bug, P. solenopsis in Field

Feeding Potential of Larval Instars

The feeding rate of larval instars increased with age and as they underwent successive moulting to the next instar. The results in Fig.4 further indicate the feeding rate per day of different larval instars. The first instar consumed (19.0±0.16) mealy bug, second instar (23.7±0.47), third instar (25.0±0.63) and fourth instar (34.6±1.41) per day/larva. Further results revealed that all larval instars of B. suturalis were voracious feeders, however the fourth instar significantly (P<0.01) devoured more number of Mealy bug/day/larva. Similarly, Lohar and Khuhro (2007) reported that the feeding of B. suturalis larvae consumed on Mealy bug was first instar (6.0), second instar (21.5), third instar (33.8) and fourth instar (42.33) per day/larva. Similarly, the data in Fig.5 further indicates the feeding rate per stage of 4th instar consumed maximum (104.3±1.71), followed by third instar (75.2±2.88), second instar (47.5±1.30) and first instar (38.0±0.24) Mealy bug/larva/stage). The consumption rate of different larval instar indicates that fourth instar consumed significantly (P<0.01) more mealy bugs as compared to other instars. Similarly, Lohar and Khuhro (2007) reported that the B. suturalis larvae consumed on Mealy bug was first instar (2.0), second instar (7.16), third instar (8.45) and fourth instar (10.58) per day/larva. Gautam and Tesfaye (2002) found the predatory potential of the predator was high in the older instars than the younger ones.

Sarhad J. Agric. Vol.28, No.2, 2012

263

Feeding Potential of Adults

The results in Fig.4 further show the feeding potential of adult male and female of B. suturalis on Mealy bug in laboratory under similar conditions. The perusal of data showed that male adult devoured (69.9±6.31 Mealy bug/day) as compared to female adult (72.03 ± 6.16 Mealy bug/day). The data in Fig.5 further indicate the feeding rate of adults that the male adult devoured (2196.9±20.10 Mealy bug/stage) as compared to female adult (2304.9±23.15 Mealy bug/stage). The statistical data show that adult female consumed significantly (P<0.01) more mealy bugs than adult male. Our results are different with Lohar and Khuhro, (2006) that adult male of B. suturalis devoured mean numbers (1566.38 Mealy bugs per life) as compared to adult female (2048.0 per life). Some ladybirds do better when they feed on certain species of prey (Dixon, 2000). Khuhro et al., (2008) reported that adult emergence was greater in female as compared to male beetles and thus the sex ratio was also higher in females as compared to males when reared on cotton Mealy bug.

Longevity Period of Larvae and Adults

The results in Fig.6 suggested that after fourth instar the larvae entered in pupal stage at 14th day of larval life. The longevity (days) of first, second larval instars was non significant (3 days each) however, third and fourth instars lived for 4 days each to transform into next life stage. The adult female lived significantly (P<0.01) more days (37) than the male (34) days on P. solenopsis in laboratory.

68.5

69

69.5

70

70.5

71

71.5

72

72.5

73

Ad.Male Ad.Female

Development Stages

Fee

ding

pot

enti

al/d

ay

P. solenopsis

0

5

10

15

20

25

30

35

40

45

L1 L2 L3 L4

Development Stages

Fee

ding

pot

enti

al/d

ayP. solenopsis

Fig. 4. Feeding potential (per day) of larval and adult stages of B. suturalis on cotton Mealy bug in field

0

20

40

60

80

100

120

L1 L2 L3 L4

Development Stages

Fee

ding

pot

enti

al/s

tage

P. solenopsis

2100

2150

2200

2250

2300

2350

Ad.Male Ad.Female

Development Stages

Feed

ing

pote

ntia

l/sta

ge

P. solenopsis

Fig. 5 Feeding potential (per stage) of larval and adult stages of B. suturalis on cotton Mealy bug in field.

Shah Nawaz Khuhro et al. Feeding potential of lady bird beetle, on cotton mealy bug …

264

32

33

34

35

36

37

38

Ad.Male Ad.Female

Development Stages

Lon

givi

ty o

f B

. sut

ural

isP. solenopsis

0

1

2

3

4

5

L1 L2 L3 L4

Development Stages

Lon

givi

ty o

f B

. sut

ural

is

P. solenopsis

Fig. 6 Longevity of B. suturalis on P. solenopsis in field

CONCLUSION AND RECOMMENDATIONS

On the basis of present studies, it is concluded that the 3rd and 4th instars were found more voracious as compared to 1st and 2nd instars. Adult female consumed more number of Mealy bugs as compared to male. It is also concluded that adults and larvae of predatory beetle prefer the crawlers of Mealy bugs. Adults consumed more Mealy bugs than larvae.

ACKNOWLEDGEMENTS

The reported data is a part of Ph.D research work of the Principal Author, carried out under HEC sponsored project “Mass Rearing of Coccinellid Predators on Different Insect Pests”. The authors are thankful to HEC and authorities of Sindh Agriculture University, Tandojam, Pakistan for providing funds and other necessary facilities.

REFERENCES

Arif, M.I., M. Rafiq and A. Ghaffar. 2002. Host Plants of cotton Mealy bug (Phenacoccus solenopsis) A new Menace to cotton Agro-eco-system of Punjab, Pakistan. Int’l. J. Agric. & Biol. 11(2): 163-167.

Dixon, A.F.G. 2000. Insect predator-prey dynamics: ladybird beetles and biological control. Cambridge Univ. Press, Cambridge. 272p.

Ferran A. and M.M. Larroque. 1977. Study of host – predator relations: the consumption and utilization of an aphid, Myzus persicae Sulz., by the different larval stages of the coccinellid Semiadalia undecimnotata Sch. (Coleoptera : Coccinellidae), Annales de Zoologie, Ecologie Animale. 9: 665-691.

Gautam, R.D. and A. Tesfaye. 2002. Potential of green lacewing, Chrysoperla carnea (Stephens) in crop pest management. New Agro-culturist. 13 (1/2): 147-158.

Hashmi, A.A. 1994. Insect pest Management (Taxonomy and identification). By National Agric. Res. Council (NARC). 3: 154p.

Hodek, I. and A. Honek. 1996. Ecology of Coccinellidae. Kluwer Academic Publisher, Dordrecht Boston, London. 446 p.

Khuhro, S.N., M.K. Lohar, S.M. Nizamani, G.H. Abro and R.D.Khuhro. 2008. Biology of lady bird beetle, Brumus suturalis Fabricius (Coleoptera:Coccinellidae) on cotton mealy bug, Phenacoccus sp. Pak. J. Agric. Agric. Engg. Vet. Sci. 24(2): 53-58.

Lohar, M.K. 2001. Applied Entomology. 2nd Ed. Kashif Public, Hyderabad. pp.96-97.

Lohar, M.K. and R.D. Khuhro. 2005. First Annual Report on Mass rearing of Coccinellid Predators on different insect pests, Submitted to Higher Education Commission, Islamabad and Sindh Agric. Univ. Tandojam, Pakistan. 211p.

Lohar, M.K. and R.D. Khuhro. 2006. Second Annual Project Report on Mass rearing of Coccinellid Predators on different insect pests, Submitted to Higher Education Commission, Islamabad and Sindh Agric. Univ. Tandojam, Pakistan. 158p.

Sarhad J. Agric. Vol.28, No.2, 2012

265

Lohar, M.K. and R.D. Khuhro. 2007. Third Annual Project Report on Mass rearing of Coccinellid Predators on different insect pests, Submitted to Higher Education Commission, Islamabad and Sindh Agric. Univ. Tandojam, Pakistan. 119p.

Michaud, S.P. 2001. Population dynamics of bean aphid (Aphis craccivora koch) and its predatory coccinellid complex in relation to crop type (Lantil, Lathyrus and Faba bean) and weather conditions. J. Entomol. Res. 18 (1): 25-36.

Saikia, P. and A. Balasubramanian, 2002. Feeding potential and larval development of Cryptolaemus montrouzieri Muls on aphids and mealybug. J. Agric. Sci. Soc. of North-East India. 13 (1): 8-11.

Solangi, G.S., G.M. Mahar and F.C. Oad. 2008. Presence and abundance of different insect predators against sucking insect pest of cotton. J. Entomol. 5(1): 31-37.