Predatory and plant-use specialization by Evarcha culicivora, an East African salticid spider A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy in Zoology in the University of Canterbury by Chan Deng Christchurch, New Zealand 2016 Table of Contents ACKNOWLEDGMENTS .................................................................................................................................. 1 ABSTRACT ........................................................................................................................................................ 7 CHAPTER ONE: INTRODUCTION ............................................................................................................... 8 REFERENCES .................................................................................................................................................................... 13 CHAPTER TWO: ADAPTIVE TIMING OF PREDATORY ACTIVITY BY A MOSQUITO- SPECIALIST PREDATOR ............................................................................................................................ 15 ABSTRACT ..................................................................................................................................................................... 16 1.0. INTRODUCTION ........................................................................................................................................................ 17 2.0. MATERIALS AND METHODS .................................................................................................................................. 22 2.1. General .................................................................................................................................................................... 22 2.2. Field sampling (Objective 1) .......................................................................................................................... 23 2.3. Daytime activity pattern under semi-field conditions (Objective 2) ............................................ 24 2.4. Night-time activity under semi-natural conditions (Objective 3) ................................................. 26 2.5. Determining whether spiders killed prey while in total darkness (Objective 4) .................... 26 2.6. Morning-afternoon differences in predisposition to capture preferred prey (Objective 5) ............................................................................................................................................................................................. 27 2.7. Morning-afternoon differences in predisposition to mate (Objective 6) ................................... 28 2.8. Morning-afternoon difference in responsiveness to lures made from preferred prey (Objective 7) .................................................................................................................................................................. 28 2.9. Morning-afternoon differences in the expression of preference when tested with lures (Objective 8) .................................................................................................................................................................. 30 2.10. Morning-afternoon differences in response to prey, mate, plant and human odour (Objective 9) .................................................................................................................................................................. 30 2.11. Data analysis ..................................................................................................................................................... 32 3.0. RESULTS .................................................................................................................................................................... 33 3.1. Field sampling (Objective 1) .......................................................................................................................... 33 3.2. Daytime activity pattern under semi-field conditions (Objective 2) ............................................ 33 3.3. Activity and predation under dim light and in total darkness (Objectives 3 and 4) ............ 34 3.4. Morning-afternoon differences in response to prey and mates (Objectives 5 and 6) ........... 34 3.5. Morning-afternoon difference in response to lures made from preferred prey (Objectives 7 and 8) ............................................................................................................................................................................... 35 3.6. Morning-afternoon differences in response to prey, mate, plant and human odour (Objective 9) .................................................................................................................................................................. 35 4.0. DISCUSSION .............................................................................................................................................................. 36 REFERENCE ...................................................................................................................................................................... 40 CHAPTER THREE: EFFECTS OF PREY AND NECTAR MEALS ON THE CAPACITY OF A MOSQUITO-SPECIALIST PREDATOR TO COMPLETE THE FIRST ACTVIE STAGE IN ITS LIFE CYCLE .............................................................................................................................................................. 58 ABSTRACT ......................................................................................................................................................................... 59 1.0. INTRODUCTION ........................................................................................................................................................ 60 2.0. METHODS AND MATERIALS .................................................................................................................................. 63 2.1. General .................................................................................................................................................................... 63 2.2. Prey and plants .................................................................................................................................................... 64 2.3. Artificial nectar ................................................................................................................................................... 65 2.4. Control trials ........................................................................................................................................................ 66 2.5. Methods specific to prey-only feeding regimes ...................................................................................... 66 2.6. Methods specific to plant-only and prey+plant feeding regimes ................................................... 67 2.7. Methods specific to feeding regimes based on using artificial nectar ......................................... 68 2.8. Data analyses ....................................................................................................................................................... 68 2.9. The use of terms .................................................................................................................................................. 69 3.0. RESULTS AND DISCUSSION ..................................................................................................................................... 69 3.1. Performance in experimental trials and performance in control trials compared ............... 69 3.2. Hatchlings that ate a single mosquito and had no access to plants or artificial nectar ..... 69 3.3. Hatchlings that had access to plants but did not eat mosquitoes ................................................. 71 3.4. Hatchlings that ate mosquitoes and also had access to plants ...................................................... 72 3.5. Hatchlings that had access to artificial nectar but no prey ............................................................ 75 3.6. Hatchlings that had access to artificial nectar containing amino acid as well as sugar ... 77 3.7. Performance when kept on full-blend artificial nectar ..................................................................... 78 3.8. Hatchlings that fed on mosquitoes in addition to having access to artificial nectar ........... 78 3.9. Hatchlings that received unlimited access to mosquitoes after being kept for 15 days with only artificial nectar .................................................................................................................................................. 80 4.0. GENERAL DISCUSSION ............................................................................................................................................ 81 4.1. Prey quantity versus prey quality ............................................................................................................... 81 4.2. Effects of the number of mosquitoes eaten when prey is the only food source ....................... 83 4.3. Evidence that female mosquitoes are superior to males as prey for E. culicivora hatchlings ....................................................................................................................................................................... 85 4.4. Performances