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DECLARATION AND APPROVAL

This work is my original work and has not been presented for an award of degree in any other university.

Name: Addis Teshome Kebede Registration No.: I80/80201/11

Signature: ______Date: ______

APPROVAL BY SUPERVISORS

This thesis has been submitted to the University of Nairobi with our approval as supervisors.

Dr. Jacques M. Kabaru University of Nairobi, School of Biological Sciences, P. O. Box: 30197-00100, Nairobi,

Signature ______Date ______

Dr. John M. Onyari University of Nairobi, Department of Chemistry, P. O. Box: 30197-00100, Nairobi, Kenya

Signature ______Date ______

Prof. Suresh K. Raina icipe- African Science for Food and Health, Commercial Programme, P.O. Box: 30772-00100, Nairobi, Kenya

Signature ______Date ______

Professor Fritz Vollrath University of Oxford, Department of Zoology, South Parks Road, Oxford OX1 3PS, UK.

Signature ______Date ______ii

DEDICATOIN

TO

MY BELOVED FAMILY AND FRIENDS iii

ACKNOWLEDGENTS

I wish to acknowledge and express my gratitude to several people and institutions that assisted and encouraged me in one or another way throughout this study. I could not have completed this study without them. My sincere appreciation goes to Drs. J. M. Kabaru and J. M. Onyari, both from University of Nairobi, for accepting to serve as my university supervisors and for their great input, critical criticism, supply of literature and numerous valuable suggestions that have shaped this thesis and the publications so far. They tirelessly and in the shortest time possible reviewed, corrected and brought in critical decisions into the drafts of this thesis. It is my pleasure to thank Professor Suresh K. Raina, who went well beyond the call of duty as ICIPE (International Centre of Insect Physiology and Ecology) supervisor for giving me a chance at the Commercial Insects Program, for his endless optimism and being cheerful and encouraging throughout it all. His constant moral support, guidance and encouragement are highly appreciated. Many thanks to Professor Fritz Vollrath, from University of Oxford, and the Oxford Silk Research Group members for providing me with excellent research facilities and patience in familiarizing me with laboratory equipments and analyses software. All my supervisors contributed a lot through their valuable comments and expert suggestions throughout the research work and the preparation of this thesis. I wish to express my profound gratitude to all colleagues at the Commercial Insect Program for their support and friendship. I also would like to thank my fellow scholars and staff of ICIPE, who were always helping and encouraging me in social interactions and research undertakings. Conversations and mutual support from them not only stimulated new insights, but also provided necessary encouragement along the way. The time I spent with them will be precious and unforgettable. Many thanks are due to German Academic Exchange Service (DAAD) for providing the scholarship and to International Fund for Agricultural Development (IFAD) for funding the research project. Thanks are also due to ICIPE and the African Regional Postgraduate iv

Program in Insect Science (ARPPIS) for providing logistical and research support. Many thanks are also to Capacity Building and Institutional Development (CBID) staff especially Mrs Lillian Igweta, Lisa Omondi and Margaret Ochenda for their constant support. Finally, I want to appreciate my family and friends for their care, unfailing encouragement, and loving support with their priceless prayers, tireless assistance and encouraging words during my whole life. It is not possible to thank everybody, but I want to thank all people who contributed to this thesis through their support and invaluable friendship. Above all, this thesis will not be complete without givi