BIO-ECOLOGY AND MANAGEMENT OF AFRICAN WHITE RICE STEM BORER, MALIARPHA SEPARATELLA RAGONOT (LEPIDOPTERA: PYRALIDAE) AT MWEA IRRIGATION SCHEME, KENYA. KEGA, VINCENT MWANGI Bsc, Botany and Zoology (University of Nairobi), Msc, Wild life Management and Control (University of Reading, United Kingdom) A THESIS SUBMITTED IN FULFILMENT OF THE REQUIREMENTS FOR THE AWARD OF DOCTOR OF PHILOSOPHY DEGREE IN AGRICULTURAL ENTOMOLOGY, DEPARTMENT OF PLANT SCIENCE AND CROP PROTECTION, FACULTY OF AGRICULTURE, UNIVERSITY OF NAIR OBI 2013 i DECLARATION This thesis is my original work and has not been presented for award of a degree in any other university or any other award. Signature …………………………. Date…………………………. Kega Vincent Mwangi This thesis has been submitted for examination with our approval as university supervisors Prof. John H. Nderitu Faculty of Agriculture Department of Plant Science and Crop Protection University of Nairobi Signature……………………………….. Date………………………….…. Prof. Florence M. Olubayo Faculty of Agriculture Department of Plant Science and Crop Protection University of Nairobi Signature……………………………….. Date……………………….……. Dr. Muo Kasina Entomology and Biotechnology National Agricultural Research Laboratories Kenya Agricultural Research Institute Signature………………………………… Date………………………..…… ii DEDICATION This degree is dedicated to my late parents (R.I.P) Honorable Isaac Kega Muthua and Alice Wangui Kega who brought me up and saw me through my education life and to rice farmers at Mwea and other irrigation schemes in Kenya who invest all their lives growing rice. iii ACKNOWLEDGEMENTS I extend my deepest appreciation to Prof. John H. Nderitu for his unwavering support during the planning and execution of the field experiments, his guidance, patience and availability. I also thank Prof. Florence M. Olubayo and Dr Muo Kasina for their scientific and technical guidance throughout the course of research, data analyses and writing the thesis. Special thanks go to Mr. Stephen Magondu the Agriculture extension officer (Mwea Rice Growers Multipurpose Society), Mr. Joel Aura and Charity Gichuru (Department of Plant Science and Crop Protection) for assisting with the logistics. The assistance in laboratory work from Simon Njinju (KARI-Mwea), Nicholas Kithuka (KARI- Katumani insect rearing facility) is acknowledged. I am grateful to Director, Kenya Agricultural Research institute (KARI) who funded the study, paid tuition fees and granted me study leave and to the Secretary/ Chief Executive Officer, National Council for Science and Technology (NCST) for funding part of the study . Special mention goes to my wife Jemima, my sons, Isaac and David and daughter Alice for their understanding, love and moral support. iv TABLE OF CONTENTS DECLARATION ................................................................................................................. ii DEDICATION ................................................................................................................... iii ACKNOWLEDGEMENTS ............................................................................................... iv LIST OF TABLES ............................................................................................................... ix LIST OF FIGURES ............................................................................................................. xi LIST OF FIGURES ............................................................................................................. xi ACRONYMS AND ABBREVIATIONS .......................................................................... xii ABSTRACT......................................................................................................................... 1 CHAPTER 1 ........................................................................................................................ 4 INTRODUCTION ............................................................................................................... 4 1.1. Background information ........................................................................................ 4 1.2. Statement of the problem ................................................................................................ 5 1.4. Objectives ...................................................................................................................... 8 1.5. Hypotheses ..................................................................................................................... 8 1.6. References ..................................................................................................................... 9 CHAPTER 2 ...................................................................................................................... 10 LITERATURE REVIEW ................................................................................................. 10 2.1. Maliarpha separatella biology and ecology .................................................................. 10 2.2. Maliarpha separatella damage on rice and importance ................................................. 11 2.3. Management of Maliarpha separatella on rice ............................................................. 12 2.5. Farmers‟ knowledge and management of rice insect pests ............................................ 16 2.6. References .................................................................................................................... 17 CHAPTER 3 ...................................................................................................................... 22 v FARMERS KNOWLEDGE AND MANAGEMENT PRACTICES OF MALIARPHA SEPARATELLA AT MWEA IRRIGATION SCHEME, KIRINYAGA COUNTY, CENTRAL PROVINCE, KENYA ................................................................................... 22 Abstract ............................................................................................................................. 22 3.1. Introduction .................................................................................................................. 23 3.2. Materials and methods .................................................................................................. 24 3.3. Results ......................................................................................................................... 29 3.4. Discussion .................................................................................................................... 38 3.5. References .................................................................................................................... 40 CHAPTER 4 ...................................................................................................................... 44 SPATIAL AND TEMPORAL FLUCTUATION OF THE AFRICAN WHITE RICE STEM BORER (MALIARPHA SEPARATELLA RAG) AT MWEA IRRIGATION SCHEME. .......................................................................................................................... 44 Abstract 44 4.2. Materials and methods .................................................................................................. 46 4.3. Results ......................................................................................................................... 50 4.4. Discussion .................................................................................................................... 56 4.5. References .................................................................................................................... 59 CHAPTER 5 ...................................................................................................................... 61 ASSESSMENT OF YIELD LOSS CAUSED BY MALIARPHA SEPARATELLA RAG. ON RICE AT MWEA , KIRINYAGA COUNTY, KENYA. ........................................... 61 Abstract 61 5.1. Introduction .................................................................................................................. 62 5.2. Materials and methods .................................................................................................. 63 5.3. Results ......................................................................................................................... 66 vi 5. 4. Discussion ................................................................................................................... 73 5.5. References ................................................................................................................... 75 CHAPTER 6 ...................................................................................................................... 78 EFFECTIVENESS OF ENTOMOPATHOGENIC NEMATODES AGAINST THE AFRICAN WHITE RICE STEM BORER MALIARPHA SEPARATELLA RAG ......... 78 Abstract 78 6.1. Introduction .................................................................................................................. 79 6.2. Materials and methods .................................................................................................. 80 6.3. Results ......................................................................................................................... 85 6.4. Discussion .................................................................................................................... 87 6.5. References ........................................................................................................... 89 CHAPTER 7 .....................................................................................................................