EFFECTS OF AGROECOSYSTEM LAND USE ON THE DIVERSITY, ABUNDANCE, AND ECOSYSTEM FUNCTIONS OF INSECT POLLINATORS OF PASSION (Passiflora edulis) CROP. Emily Nduku Kitivo Reg No. 1701/MAC/30037/2014 A Thesis Submitted in Partial Fulfillment of the Requirements for the award of the Degree of Doctor of Philosophy in Environmental Management in the School of Environment, Water and Natural Resources of South Eastern Kenya University. June, 2019 i DECLARATION I understand that plagiarism is an offence and I therefore declare that this thesis is my original work and has not been presented to any other institution for any other award. Signature………………………. Date…………………… Emily Nduku Kitivo Reg No. 1701/MAC/30037/2014 Department of Environmental Science and Land Resources Management We confirm that the work reported in this thesis was carried out by the candidate under our supervision and has been submitted with our approval as supervisors. Signature……………………. Date………………… Professor Gideon H. Nyamasyo School of Biological Sciences University of Nairobi Signature……………………… Date…………………. Dr. Jacinta M. Kimiti Department of Environmental Science and Land Resources Management South Eastern Kenya University Signature…………………. Date………………… Dr. Josphert N. Kimatu Department of Biological Sciences South Eastern Kenya University ii ACKNOWLEDGEMENTS To God be all the glory for guiding me in all my academic endeavors and for the gift of life. I am grateful to Prof Gideon Nyamasyo for being my supervisor and providing me high quality scientific assistance in pollination ecology. You have always been patient in reading my work and have motivated me in my academic pursuit. I appreciate Dr. Jacinta M. Kimiti for introducing me to the field of Environmental Management, providing technical guidance in research methodology, critical comments and enhancing my knowledge in environmental science. I thank Dr. Josphert Kimatu for providing useful comments and outstanding contribution to this work. I have learned a lot of things from you especially how to overcome academic pitfalls. I am indebted to Jane Macharia, Mary Mbatha, and late Joseph Mugambi from the National Museums of Kenya for technical assistance in the field and helping identify specimens collected during this work. I am much obliged to the National Commission on Science, Technology, and Innovation (NACOSTI) for financial support and making my research possible and successful. I express my gratitude to South Eastern Kenya University especially the Department of Environmental Science and Land Resources Management for accepting my registration as a post-graduate student. I sincerely thank The Ministry of Agriculture, Machakos Sub County Mua ward, Madam Diana Komu and Mr. Kithae for their participation during data collection. I appreciate the Mua Location chief Ndeti and the group of farmers who allowed me to do the fieldwork and collect data in their farms and land. I thank most warmly my family and friends for moral support. iii DEDICATION This thesis is dedicated to The All Mighty God for His love and grace, My parent Margaret Titah for prayers and guidance and, My lovely daughters Abigail Mumo and Judy Ndanu for their love, support, and encouragement. iv TABLE OF CONTENTS Title Page DECLARATION .......................................................................................................... II ACKNOWLEDGEMENTS ......................................................................................... III DEDICATION ............................................................................................................. IV TABLE OF CONTENTS .............................................................................................. V LIST OF TABLES .................................................................................................... VIII LIST OF FIGURES ..................................................................................................... IX LIST OF PLATES ........................................................................................................ X LIST OF APPENDICES .............................................................................................. XI ABBREVIATIONS AND ACRONYMS .................................................................. XII DEFINITION OF TERMS ....................................................................................... XIV ABSTRACT .............................................................................................................. XVI 1.0 CHAPTER ONE: INTRODUCTION ...................................................................... 1 1.1 BACKGROUND INFORMATION ........................................................................... 1 1.2 STATEMENT OF THE PROBLEM ............................................................................... 5 1.3 OBJECTIVES OF THE STUDY .................................................................................... 7 1.3.1General Objective ........................................................................................... 7 1.3.2 Specific Objectives ......................................................................................... 7 1.4 HYPOTHESES ......................................................................................................... 7 1.5 SIGNIFICANCE OF THE STUDY ................................................................................ 8 1.6 SCOPE OF THE STUDY ............................................................................................. 9 2.0 CHAPTER TWO: LITERATURE REVIEW ........................................................ 11 2.1 ECOSYSTEM FUNCTIONS, BIODIVERSITY, AND ENVIRONMENTAL NICHE CONCEPTS .................................................................................................................................. 11 2.2 IMPORTANCE OF POLLINATION AS AN ECOSYSTEM FUNCTION. ............................. 14 2.3 INSECT POLLINATOR DIVERSITY .......................................................................... 16 2.3.1Order Lepidoptera (butterflies and moths) .................................................. 18 2.3.2Order Coleoptera (beetles and weevils) ....................................................... 19 2.3.3Order Hymenoptera (ants, bees, wasps) ...................................................... 19 2.3.4Order Diptera (flies, mosquitoes, midges) ................................................... 20 2.3.5 Order Orthoptera (crickets, grasshoppers, locusts). ................................... 20 2.3.6 Order Araneae (spiders) .............................................................................. 21 2.3.7 Order Blattodea (cockroaches) ................................................................... 21 2.3.8 Order Hemiptera ......................................................................................... 21 2.4 EFFECTS OF LAND USE TYPE ON INSECT DIVERSITY AND ABUNDANCE ................. 23 2.5 ECOLOGY OF CARPENTER BEE ............................................................................. 24 2.6 ECOLOGY OF PASSION FRUIT CROP ...................................................................... 27 v 2.7 EFFECT OF AGRO-CHEMICALS ON INSECT DIVERSITY AND ABUNDANCE .............. 29 2.8 THE ASSOCIATION BETWEEN PLANT SPECIES AND DIVERSITY OF POLLINATORS ... 34 2.9 CONCEPTUAL FRAMEWORK ................................................................................. 37 3.0 CHAPTER THREE: MATERIALS AND METHODS ........................................ 39 3.1 INTRODUCTION .................................................................................................... 39 3.2 GENERAL MATERIALS AND METHODS................................................................. 39 3.3 STUDY AREA ....................................................................................................... 39 3.4.1 Sampling design used to determine the trends of the diversity and abundance of insect pollinators in different land use types and passion fruit set in contrasting AEZ .................................................................................................... 41 3.4.1.1 Sweep net .............................................................................................. 41 3.4. 1.2 Pantrap ................................................................................................. 42 3.4.1.3 Line transect .......................................................................................... 44 3.4.2 Sampling design to determine passion fruit set ........................................... 44 3.4.3 Sampling Design used to assess the use of agrochemicals and their impact on the insect pollinators in the agro-ecosystems. ................................................. 45 3.4.4 Sampling Design to determine the association between plant diversity and insect species richness .......................................................................................... 47 3.5 DATA ANALYSIS .................................................................................................. 48 3.5.1 Data analysis for insect diversity and abundance ....................................... 48 3.5.2 Data analysis to determine passion fruit set ............................................... 48 3.5.3 Data Analysis on the use of agrochemicals and their impact on the insect pollinators in the agro-ecosystems. ...................................................................... 49 3.5.4 Analysis of data to determine the association between plant diversity