UNIVERSITI PUTRA MALAYSIA

BIOCONTROL DYNAMICSTTRICHOGRAMMA SPP ASSOCIATED WITH HELICOVERPA ARMIGERA (HUBNER) IN ETHIOPIAN MIXED

VEGETATION ECOSYSTEMS

MULUGETA NEGERI TULU.

FP 2005 20

BIOCONTROL DYNAMICS OF TRICHOGRAMMA SPP ASSOCIATED WITH HELICOBRPA ARMIGERA (HUBNER) IN ETHIOPIAN MIXED

VEGETATION ECOSYSTEMS

BY

MULUGETA NEGERI TULU

Thesis Submitted to the School of Graduate Studies, Universiti Putra Malaysia, in Fulfilment of the Requirements for the Degree of

Doctor of Philosophy

May 2005

To:

"My beloved Wife, Tigist Tadesse

My Daughter Hawi Mulugeta,

My Son Yomiyu Mulugeta and the rest of my families"

for their much tried patience and support.

"Success is goingfiom failure to failure without loss of enthusiasm"

Winston Churchill.

Abstract of the thesis presented to the Senate of the Universiti Putra Malaysia in fulfilment of the requirement for the degree of Doctor of Philosophy

BIOCONTROL DYNAMICS OF TRICHOGRAMMA SPP ASSOCIATED WITH HELICOWRPA ARMIGERA (HUBNER) IN ETHIOPIAN MIXED

VEGETATION ECOSYSTEMS

MULUGETA NEGERI TULU

May 2005

Chairman: Associate Professor Rohani Ibrahim, PhD

Faculty: Agriculture

The natural occurrence of egg parasitoids was assessed by investigating the

compatibility of Trichogramma spp. associated with the African bollworm,

Helicoverpa armigera (Hiibner) under mixed vegetation ecosystems. Field and

laboratory investigations were conducted to study the diversity, species composition,

biology and effectiveness of recovered Trichogramma spp. and other egg parasitoids

on H. armigera.

Assessments on the diversity of egg parasitoids conducted on farmers' fields on 50

randomly selected sites from four contrasting agro-ecosystems indicated that there

were four main groups of Hymenopteran egg parasitoids. They were the two

Telenomus spp. (Scelionidae), two Trichogrammatoidea spp. nr. lutea and nr

armigera (Trichogrammatidea), two Trichogramma spp. nr. mwanzia and nr.

bournieri (Trichogrammatidae) and lastly a number of unidentified species. The

natural field parasitism was estimated to be 33%; parasitism of the recovered egg

parasitoid species according to locations varied from 27 to 40% while that of different

crops (cotton, tomato and pepper) varied from 25 to 57%. Among those recovered

from the surveyed agro-ecological locations, Trichogramma sp. nr. bournieri was

recovered on various canopy structures of cotton, tomato and maize, indicating that it

has a broader niche. Egg parasitoid abundance and species composition analyzed by

the Czekanowski coefficient and Shannon index indicated that Tsp. nr. bournieri,

Telenomus sp. and Tsp. nr. mwanzia were widespread in both low (Afar) and high

altitude (Guder) agro-ecologies.

The abundance of H. armigera egg and its egg parasitoids in two benchmark sites at

extreme altitudes (740 and 2034 meter above sea level) during the main and off-

seasons on eight crop types varied with respect to crop type, season and altitude. In

general, parasitism was higher during the main season. At lower altitudes, the highest

count of parasitized eggs was from pigeon peas where the parasitoid Telenomus sp.

was the most abundant. At higher altitudes, the highest number of parasitized eggs

was recorded from tomato. The first appearance of targeted host egg during the off-

season at lower altitude was in November and it was the highest number recorded. At

Guder, (high altitude) during the off-season, H armigera eggs and their parasitoids

were recorded from November to January in tomatoes and pigeon peas with the

highest parasitism recorded in January in both crops.

Observations revealed that male Tsp. nr. bournieri emerged 7-12 minutes earlier than

the females. The males stood guard around the parasitized eggs awaiting the emerging

female for copulation. The overall frequency distribution of the number of adults

emerged daily was positively skewed for both sexes. The duration of immature and

adult stages for T.sp. nr. bournieri was 9.25 and 3 days, respectively, whereas for Tsp.

nr. mwanzia it was 9.35 and 2.35 days, respectively.

tllPUET'AKAAN SULTAN ABDUL UNIVERSITI WTRA MALkYSlA

Suitability and acceptability of H. armigera egg for ovipostion of the native Tsp. nr.

bournieri, Tsp. nr. mwanzia and a Telenomus sp. was studied under laboratory

conditions. Telenomus sp. failed to perform when held under laboratory conditions.

The reason for this is not clear. The acceptability and suitability level .by the two

Trichogramma parasitoids varied with age and density of H. armigera eggs. In

general, severity of parasitism decreased with increasing host egg age while searching

or foraging increased with increasing host egg age.

Functional responses studied on various factitious host egg densities exposed to

different numbers and combinations of parasitoid species showed the mean rate of

parasitism was highest when the host eggs were exposed to an individual species of

multiple females of four to eight. The mean parasitism rate increased with increasing

number of adults.

The host egg parasitism by Tsp. nr. bournieri and Zsp. nr. mwanzia was highly

affected at temperature intervals between 10 and 40°C. The number of adult female

progeny was greater than the males at different level of temperature. Trichogramma

sp. nr. bournieri had a wider spectrum and its optimum temperature was between 10

and 35°C. The high efficiency of parasitism by Tsp. nr. bournieri and its superior

searching capacity, as revealed by studies done under the controlled conditions of the

greenhouse (under cloth mesh cage) and lathehouse (under open air cage) led to the

conclussion that it was potentially promising to be exploited as a biocontrol agent

against H. armigera.

Abstrak Tesis Yang Dikemukakan Kepada Senat Universiti Putra Malaysia Sebagamemenuhi Keperluan Untuk Ijazah Doktor Falsafah

DINAMIK KAWALAN BIOLOGI TRICHOGRAMMA SPP. BERKAITAN DENGAN HELICOWRPA ARMIGERA (HUBNER) DI DALAM EKOSISTEM

PELBAGAI TUMBUHAN DI ETHIOPIA

Oleh

MULUGETA NEGERI TULU

Pengerusi:

Fakulti:

Profesor Madya Rohani Ibrahim, PhD

Pertanian

Kejadian semulajadi parasitoid telur telah dinilai secara menyiasat keupayaaan

penyesuaian Trichogramma spp dengan ulat kapas Afrika, Helicoverpa armigera

(Hiibner) di dalam ekositem pelbagai tumbuhan. Penyiasatan di lapangan dan makmal

telah dijalankan untuk mengkaji kepelbagaian, komposisi spesies, biologi dan

keberkesanan Trichogramma spp. yang ditemui dan lain-lain parasitoid telur ke atas

H. armigera.

Penilaian terhadap diversiti parasitoid telur di 50 buah ladang yang dipilih secara

raw& daripada empat agroekosistem berlainan menunjukkan terdapat empat

kumpulan utama parasitoid telur Hymenoptera. Mereka adalah dua Telenomus spp

(Scelionidae), dua Trichogrammatoidae spp .nr lutea dan nr. armigera

(Trichogrammatidae), dua Trichogramma spp. nr. mwanzai dan nr. bournieri

(Trichogrammatidae) dan sebilangan speses yang belum dapat dikenal pasti.

Parasitisme semulajadi di lapangan telah dianggarkan sebanyak 33%; parasitisme

spesies parasitoid telur yang ditemui mengikut lokasi merangkumi 27% hingga 40%

sementara daripada tanaman yang berbeza (pokok kapas, tomato dan chili)

merangkumi 25% hingga 57%. Di antara yang telah ditemui dari lokasi aroekologi

yang disurvei, Trichogramma sp. nr. Bournieri telah ditemui di dalarn pelbagai

struktur sudur pokok kapas, tomato dan jagung, menunjukkan bahawa ia mempunyai

niche luas. Limpahan parasitoid telur d m komposisi spesies yang dianalisis secara

koefisyen Czekanowski dan indeks Shannon menyatakan bahawa T. sp. nr. bournieri,

Telenomus sp. dan T. sp. nr. mwanzai adalah tersebar luas di kedua-dua agroekologi

altitude rendah (Afar) dan altitude tinggi (Guder).

Kelimpahan telur H.armigera dan parasitoid telurnya di dua tapak tandaras pada

altitud lampau (740 dan 2034 masl) pada musim utama dan luar musim ke atas lapan

jenis hasil tanaman berbeza-beza mengikut jenis tanaman, musim dan altitud. Secara

umumnya, parasitisme adalah tinggi mengikut musim utama. Di altitud rendah,

jumlah paling banyak telur yang diparasit adalah dari pigeon peas di mana parasitoid

Telenomus sp. adalah yang terbanyak. Di altitude tinggi, bilangan tertinggi telur yang

diparasit telah direkodkan dari tomato. Kemunculan pertama telur perumah sasaran

pada luar musim di paras altitud rendah adalah pada bulan November dan merupakan

catatan yang tertinggi. Di Guder (altitud tinggi) pada luar musim, telur H. armigera

dan parasitoidnya telah dicatatkan dari November hingga pada tanaman tomato dan

pigeon-peas dengan parasitisme yang tertinggi dicatatkan pada bulan Januari bagi

kedua-dua tanaman.

Penelitian mendedahkan bahawa induk jantan T. sp. nr. bournieri muncul 7-12 minit

lebih awal daripada betina. Induk jantan akan mengawal berhampiran telur yang

diparasit sambil menunggu penjelmaan betina untuk mengawan. Keseluruhan taburan

frekuensi bilangan dewasa muncul setiap hari adalah positip berat sebelah bagi kedua-

dua jantina. Jangka masa peringkat belum dewasa dan dewasa untuk T. sp. nr.

bournieri adalah masing-masing 9.25 dan 3 hari, manakala untuk T. sp. nr. mwanzia

pula masing-masing 9.3 5 dan 2.3 5 hari.

Kesesuaian dan penerimaan telur H. armigera untuk dioviposisi spesies asli T. sp. nr.

bournieri, T. sp. nr. mwanzia dan Telenomus sp. telah dikaji di makmal. Telenomus sp.

gaga1 bertindak apabila terkurung di dalam keadaan makmal. Sebabnya masih belum

jelas. Paras penerimaan dan kesesuaian untuk kedua parasitoid Trichogramma

dibedakan dengan usia dan kepadatan telur H. armigera. Secara umumnya keterukan

parasitisme telah menurun dengan peningkatan usia telur sementara pencariannya

menurun dengan peningkatan usia telur perumah.

Kajian respon fungsian ke atas kepadatan telur perumah buatan yang telah didedahkan

kepada pelbagai bilangan dan kombinasi spesies parasitoid menunjukkan min kadar

parasitisme adalah tertinggi apabila telur utama telah didedahkan kepada spesies

tunggal dari empat hingga lapan betina. Min kadar parasitisme telah meningkat

dengan peningkatan bilangan dewasa.

Parasitisme telur perurnah amat dipengaruhi oleh T. sp. nr. bournieri dan T. sp. nr.

mwanzia amat dipengaruhi oleh suhu di antara 10 " C dan 40 " C. Bilangan anak betina

yang dewasa adalah melebihi bilangan jantan pada aras suhu yang berlainan. T. sp. nr.

bournieri mempunyai spectrum lebih luas dan suhu optimum baginya adalah di antara

10 " C dan 35 " C. Keberkesanan parasitisme yang tinggi oleh T. sp. nr. bournieri dan

keupayaan pencarian yang unggul, sebagaimana yang telah didedahkan dalam kajian

yang dibuat di bawah keadaan yang terkawal rumah hijau (sangkar kain) dan rumah

lapis (sangkar terbuka) telah menjuruskan kepada kesimpulan bahawa ia mempunyai

harapan berpotensi untuk diperalatkan sebagai agen pengawalan biologi ke atas H.

armigera.

ACKNOWLEDGEMENTS

"Almost everything you do will seem insignzficant, but it is very important that you do it anyway. " Gandhi

First, thanks to my senior supervisor Professor Dr. Yusof Hussein, for providing an

atmosphere where students have the freedom to explore, make mistakes, have fun; and

in the process learn about science and our selves. Professor Dr. Yusof Hussein has

served as a chairman of the supervisory committee and he was able to visit Ethiopia

and the experimental sites and laboratory activities besides his regular support before

his retirement. Really, I thank him for his patience and enthusiasms, which has been

encouraging to me

I would like to extend my deepest appreciation to all my supervisory committee

members: Associate Professor Dr. Rohani Ibrahim, Professor Dr. Ahmad Said Sajap

and Professor Dr. Yusof Ibrahim for their support, guidance and counseling during the

course of my research and study. Special acknowledgement is also extended to them

for their trust in me and made my academic accomplishments possible and for their

critical review all the content of the thesis.

I am very much grateful to Professor Dr. Yusof Ibrahim for his continuous help and

consultations that he showed me scientist approach even while he was not my

supervisory committee membership and especially at the time of my immediate

supervisor Professor Yusof Hussein was not around due to other administrative

responsibilities. Later, Professor Dr. Yusof Ibrahim as a supervisory committee

member helped me a lot also in critically reviewing and improving the status of my

thesis as it would be.

After the retirement of Prof Yusof Husin, Associate Professor Dr. Rohani Ibrahim

took over the responsibilities of the chairperson voluntarily and showed interest to

guide me and shape all my thesis works. Professor Dr. Ahrnad Said Sajap allowed me

to use his laboratory; image magnifier and microscope for taking pictures of egg

parasitoid specimens and well advised me how to proceed in writing thesis. Thank you

all for your kindness and help.

I am very much grateful to Dr. Sithanantham (from ICIPE), Dr. Mohamed and Mr

Ketama (PPRC-EARO) for their comments and suggestions they made during the

evaluations of my initial proposal. A special thanks to Dr. Sithanantham for his

assistance, friendship and guidance during my field works in Ethiopia and support me

to focus on Trichogramma and other egg parasitoids.

I am indebted to my circle of friends, lab mates, who have shared their views, hearts

and showed interest for consulting, reminding and processing some management

issues what is really important. Thanks especially to Saripah, Sulaiman, Syari for

helping me through various troubles.

I also like to acknowledge the support of the School of Graduate Studies of Universiti

Putra Malaysia, Agricultural Faculty, Plant Protection Department, the Graduate

Students Coordinator, Graduate Seminar Coordinator, Lecturers and all higher

officials as well as supportive staffs of the University, I thank them for their help,

kindness approach and hospitality at every level.

I would like to express my sincere gratitude to my colleagues Mr Erenso, Mandefro

and Abayneh (from Agriculture, UPM), Siyum and Deribe (from forestry, UPM), for

their help, consult and who were always friendly and encouraged me in this study.

The technical assistance provided by Zerihun Beshir, Aberash Chala, Dagnachew,

Sharow (From PPRC); Yosef, and Abiyi and other field and technical assistants from

MelkaWerer research center to my thesis work was very efficient and highly

appreciated. I greatly acknowledged their contribution.

I am very much grateful to Development Agents of Ministry of Agriculture (MoA) at

respective districts where survey or field assessments contacted. Mr. Asfaw Balina,

Miss Mulu Brihane (from Sasiga MoA); Mr.Eba (from Nekempte, Jato irrigation site);

Mr. Abera (from Getarna MoA) and Mr. Ahrned (from Anno-Gobu seyo MoA) are

highly acknowledged for their assistance in site guidance, collection and all necessary

information.

I wish to express my deep appreciation to Mr. Fikadu a Head of Plant Protection

Division in Nura era state farm and all insect assessors and farm management units of

this enterprise for their assistance in insect collection, field evaluations and

assessments, permission to conduct my trial in their farm fields and positive co-

operations and help. Also local farms from were I took data are acknowledged.

I am especially grateful to Worer research center of EARO in Afar for granting

permission to carry out field investigations on their experimental fields and for their

hospitality and co-operation.

I am indebted to the management staffs, lecturers and farm management unit of Ambo

College of Agriculture for granting permission to use their experimental field at Guder

to carry out on-station investigations and to assess all their tomato fields. Thanks for

Mr Kinfe for his concern and arrangement for both on-station experiment and selected

voluntary farms for continuous assessment on their tomato fields.

I am extremely grateful to the Ethiopian Agricultural Research Organization (EARO)

and Plant Protection Research Center for granting me the period of study leave. I wish

also to thank Dr. Tadesse GIMedhine (EARO head office), Dr. Emma Getu (MRC),

Dr Bayeh Mulatu and Kemal Ali (HRC) of EARO for their contribution in giving me

moral and advice in the subject matter.

Thanks to all EARO library staffs Mr. Aklilu, Miss Boge, Mintilu and from EARO

information department Mr Abebe, Mr Girum and from GIs Mr. Demeke and Mr

Engida and others for their help. EARO training staff Mr. Mulugeta, Miss Roman,

Mr.Girma and Abara were really assisting me a lot, thank you very much all of you.

I wish to thank Ethiopian Government and EARO for awarding me the Agricultural

Research and Training Project (ARTP) program fellowship for making this study

possible and successful. Somehow, it seems woefully inadequate to address people of

EARO management, ARTP and training unit of EARO, budget and finance

department of PPRC and all technical staffs what they given to me I simply want to

express my heartfelt gratitude for their support on the way of my life. I wish also to

thank Dr. Abera bekele who was followed up, assisted and helped my family members

while I was on the study leave.

Finally, I want to thank my family, my parents, whose limitless support has allowed

me to become who I am and make me feel like I never have to settle for anything. The

support made by Asnake, Mintesinot, Alarnaz and Genet and others are much

acknowledged. My wife Tigist Tadesse, for all the sacrifices she made, her tolerance,

her patience, and her love. Finally my children Hawi and Yomiyou, who provide both

balance and inspiration, Daddy's coming home. I thank all of you for your interest

and encouragement during my stay abroad for this study.

I certify that an Examination Committee met on 13th ~a~ 2005 to conduct the final examination of Mulugeta Negeri Tulu on his Doctor of Philosophy thesis entitled "Biocontrol Dynamics of Trichogramma spp Associated with Helicoverpa armigera (Hiibner) in Ethiopian Mixed Vegetation Ecosystems" in accordance with Universiti Pertanian Malaysia (Higher Degree) Act 1980 and Universiti Pertanian Malaysia (Higher Degree) Regulation 198 1. The Committee recommends that the candidate be awarded the relevant degree. Members of the Examination Committee are as follows:

DZOLKHIFLI OMAR, PhD Professor Faculty of Agriculture, Universiti Putra Malaysia (Chairman)

RITA MUHAMAD, PhD Associate Professor Faculty of Agriculture, Universiti Putra Malaysia (Member)

SYED TAJUDDIN SYED HASSAN, PhD Professor Faculty of Science, Universiti Putra Malaysia (Member)

ABU HASSAN BIN AHMAD, PhD Professor School of Biological Science, Universiti Sains Malaysia (Independent Examiner)

Professor l Ljeputy ~ e a n School of Graduate Studies Universiti Putra Malaysia

Date:

This thesis submitted to the Senate of Universiti Putra Malaysia and has been accepted as fulfillment of the requirement for the degree of Doctor of Philosophy. The members of the Supervisory Committee are as follows:

ROHANI IBRAHIM, PhD Associate Professor Faculty of Agriculture Universiti Putra Malaysia (Chairman)

AHMAD SAID SAJAP, PhD Professor Faculty of Forestry Univesrsiti Putra Malaysia (Member)

YUSOF BIN IBRAHIM, PhD Professor Faculty of Agriculture Universiti Putra Malaysia (Member)

AINI IDERIS, Ph.D. ProfessorIDean School of Graduate Studies Universiti Putra Malaysia

DECLARATION

I hereby declare that the thesis is based on my original work except for quotations and citations which have been dully acknowledged. I also declare that it has not been previously or concurrently submitted for any other degree at UPM or other institutions

xvii I

TABLE OF CONTENTS

DEDICATION ABSTRACT ABSTRAK ACKNOWLEDGEMENTS APPROVAL DECLARATION LIST OF TABLES LIST OF FIGURES ABBREVATIONS

CHAPTER

1 INTRODUCTION 1.1 General Introduction 1.2 The Significance of the Study 1.3 Specific Objectives

2 LITRATURE REVIEW Overview of Helicoverpa armigera (Hiibner) Biological Control: Concepts and Overview Natural Enemies Type of Biological Control Biodiversity in Agro-Ecosystems Species Diversity; Species Richness and Diversity Indices Coexistence / Compatibility / and Competition of Natural Enemies Parasitoids as Biological Control Agents Interactions among Host Plants; Host Insects; and Parasitoidsl Predators Semiochemically Mediated Interaction chemically Mediated Interactions Physically Mediated Interactions Biological Control with Egg Parasitoids Size and Distribution of Trichogramma Taxonomy of Trichogramma Distribution and Faunal Relationships Biology and Life Cycle of Trichogramma Use of Trichogramma in Biological Control Functional Response of Trichogramma Species Parasitoid Quality Host Preference and Suitability of Trichogramma Host Plant Preference of Trichogramma Biological Control Agents and Pesticides

MATERIALS AND METHODS 3.1 General

3.1.1 Insect Cultures 3.1.2 Experimental Designs and Statistics

Page

11 . . . 111

vi X

xv xvii xxi

xxiv xxxi

1

1 1 7 9

11 11 18 2 1 2 3 24 29 30 37

xviii 4 II

4 DIVERSITY OF TRICHOGRAMMA WASPS ATTACKING Helicoverpa armigera IN MIXED VEGETATION ECOSYSTEMS 4.1 Introduction 4.2 Materials and Methods

4.2.1 Site Selection 4.2.2 Time of the Assessments 4.2.3 Collections of H. armigera Eggs and Larvae 4.2.4 Laboratory Culture 4.2.5 Parasitoids Identification 4.2.6 Statistical Treatment of Data Results 4.3.1 On-Farm Assessments 4.3.2 Assemblage Native Egg Parasitoids 4.3.3 On station assessments 4.3.4 Seasonal Occurrence of Host Insect and Its Egg Parasitoids Discussion Conclusions

5 SOME ASPECTS OF BIOLOGY OF NATIVE TRICHOGRAMM SPP 5.1 Introduction 5.2 Materials and Methods 5.3 Results 5 4 Discussion 5.5 Conclusions

6 ACCEPTABILITY AND SUITABILITY OF H. armigera (Hiibner) EGGS 6.1 Introduction 6.2 Materials and Methods 6.3 Results 6.4 Discussions 6.5 Conclusion

7 STUDYING THE FUNCTIONAL RESPONSE OF THE NATIVE EGG PARASITOIDS ON FACTITIOUS HOST 7.1 Introduction 7.2 Materials and Methods 7.3 Results 7.4 Discussion 7.5 Conclusion

EFFECTS OF TEMPERATURES ON THE FUNCTIONAL RESPONSE AND DEVELOPMENT OF TRICHOGRAMM SPP 8.1 Introduction 8.2 Materials and Methods 8.3 Results 8.4 Discussion 8.5 Conclusion

9 EVALUATION OF THE SELECTED EGG PARASITOID EFFICIENCY UNDER CONTROLLED CONDITIONS 247 9.1 Introduction 247

Materials and Methods Results Discussion Conclusion

10 GENERAL DISCUSSION AND CONCLUSION

REFERENCES APPENDICES BIODATA OF THE AUTHOR

LIST OF TABLES

Table Page

Typical annual rainfall calendar and distributions (mm) in Ethiopia 79

Major altitudes and climatic regions of Ethiopia

Summary of field parasitism within cotton crop during the off and main -season at location 1 (afar)

Summary of field parasitism within tomato crop during off and main seasons at location 1 (Afar)

Summary of field parasitism within pepper crop during off and main- season at location 1 (Afar)

Summary of field parasitism within cotton crop assessed during off and main- season at location 2 (east shewa)

Summary of field parasitism within maize crop assessed during off and main- season at location 2 (east Shewa)

Summary of field parasitism within tomato crop assessed during off and main- season at location 2 (east Shewa)

Summary of field parasitism within tomato crop during off and main- season at location 3 (west Shewa)

Summary of field parasitism within maize crop during off and main- season at location 3 (west Shewa)

Summary of field parasitism within tomato crop during off and main- season at location 4 (east Wollega)

Summary of field parasitism (%) in all four locations

Egg parasitoids mean density, mean frequency and mean important values estimated by location 120

Diversity (H') and Equitability (J) index of the egg parasitoids recovered

Chi square test for egg parasitoid species distributions

Copulation time (second) of T. sp. nr. bournieri under laboratory conditions (n= 10) (microscopic observations)

Mean percent T. sp.nr. mwanzai adult emerged from mean number of host egg parasitized per host age

Acceptance of different h. armigera egg age by T. sp. nr. mwanzai in relation to mean encounter count

Mean percent T. sp. nr. mwanzai adult emerged from host egg parasitized per host egg density

Acceptance of different H. armigera egg densities by T. sp.nr. mwanzai in relation to encounter count

Mean percent T sp.nr. bournieri adult emerged from host egg parasitized per host age

Acceptance of different H. armigera egg age by T. sp.nr. bournieri in relation to encounter count

Mean percent T. sp.nr. bournieri adult emerged from host egg parasitized per host egg density

Mean host egg parasitized, encounter counts and accepted encounter count ratio of. T. sp.nr.bournieri on different host egg densities. 196

An exposure of a single female parasitoid of each species to different densities of host eggs

An exposure of a multiple (2,4 and 8) adult female parasitoids of the same species to different densities of host eggs

An exposure of a multiple adult female parasitoid combination arrangement of T sp .nr. mwanzai and T. sp.nr. bournieri to different densities of host eggs.

mean host eggs parasitized that exposed to variable numbers adult parasites fiom the same species and host egg densities offered under laboratory conditions.

Parameters estimates of the functional response of T. sp .nr. mwanzai exposed to the variable number of adult of parasitoids

Parameters estimates of the functional response of T. sp. nr. bournieri to the variable number of adult of parasite with variable host egg density

Mean interaction effect of variable adult numbers of different species x different level of host egg densities on total number of host egg parasitism per batch.

Parameters estimates of the functional response of multiple Trichogramma exposed to the variable number of adult of parasitoids with variable host egg density

Summary of developmental period of immature stage of trichogramma sp.nr . bournieri under laboratory conditions

Summary of the number of adult progeny and sex ratio of T. sp. nr. bournieri at different temperature levels 239

Effect of temperature ("c) on mean progeny production of adults of trichogramma sp.nr.brournieri at different temperature levels under laboratory conditions

Temperature ("c) effects on storage and longevity of adult female and male of T. sp. nr, bournieri at different temperature levels under laboratory conditions

LIST OF FIGURES

Figure

2 1

Page

Adult Helicoverpa armigera (a) resting adult (b) buff hind wings (c) underside view.

Eggs of H. armigera laying pattern

Later instar (4-5th) caterpillar of H. armigera

Pupae of H.armigera on the top of the soil in the pot

Life cycle of H. armigera

Hierarchical relationships of the study of compatibility of native trichogramma spp

Aquarium plastic container consists of artificial diet for rearing factitious host

Plastic cups used as ovipositional cages for factitious host and egg harvesting

Big and small sized vials used to expose host eggs, adult egg parasitoids and study their parasitism rates under laboratory conditions

Factitious host insect and targeted host insects rearing equipments and arena

Traditional practices and mixed farming systems (mosaic pattern) of Ethiopia) 74

One of the monoculture cropping pattern of cotton at upper awash rift valley areas, where eggs of H . armigera collected and field researches were conducted. 74

Locations of study areas in different parts of Ethiopia (1= Afar, 2= east Shewa, 3= west Shewa and 4= east Shewa) 8 1

Locations of the sampling sites in east Wollega (Loc=4)

Location of the sampling sites in west Shewa (Loc= 3)

Location of the sampling sites in east Shewa (Loc =2)

Locations of sampling sites in Afar (Loc. 1)

Collection of larvae from chick pea field using quadrant and Entomological net