Prey Preferences of Specialized Jumping Spiders (Araneae: Salticidae)
Total Page:16
File Type:pdf, Size:1020Kb
PREY PREFERENCES OF SPECIALIZED JUMPING SPIDERS (ARANEAE: SALTICIDAE) A thesis submitted in fulfilment of the requirements for the Degree of Doctor of Philosophy in Zoology at the University of Canterbury by paiqin Li University of Canterbury 1996 ~W exl- 4~ , q CONTENTS List of Tables List of Figures ABSTRACT 1 SECTION I: INTRODUCTION CHAPTER 1: Introduction 3 SECTION II: MVRMICOPHAGIC SALTICIDS CHAPTER 2: Prey-capture techniques and prey preferences of Habrocestum pulex (Hentz), an ant-eating jumping spider (Araneae: Salticidae) from North America 11 CHAPTER 3: Prey-capture techniques and prey preferences of five species of ant-eating jumping spiders (Araneae: Salticidae) from the Philippines 29 SECTION III: ARANEOPHAGIC SALTICIDS CHAPTER 4: Prey preferences of Portia fimbriata, an araneophagic, web-building jumping spider (Araneae: Salticidae) from Queensland 56 CHAPTER 5: Prey preferences of Portia africana, P. labiata and P. schultzi, araneophagic, web-building jumping spiders (Araneae: Salticidae) from Kenya and Sri Lanka 95 SECTION IV: FINE TUNING OF PREFERENCE IN RELATION TO RISK CHAPTER 6: The biology of Scytodes sp. indet., a spitting spider (Araneae: Scytodidae) from ii Los Banos: silk utilization, maternal, social predatory behaviour 115 CHAPTER 7: Predator-prey interactions between web-invading jumping spiders (Araneae: Salticidae) and Scytodes sp. indet., a spitting spider (Araneae: Scytodidae) from Los Banos, the Philippines 145 CHAPTER 8: Fine tUhing of preference of Portia labiata, an araneophagic, web-building jumping spider (Araneae: Salticidae), for a spitting spider, Scytodes sp. indet. (Araneae: Scytodidae) from the Philippines 158 SECTION V: EFFECT OF PREFERRED DIET ON FITNESS CHAPTER 9: Influence of preferred diet on survivorship and growth in Portia fimbriata, an araneophagic jumping spider (Araneae: Salticidae) from Queensland 169 SECTION VI: DISCUSSION CHAPTER 10: Prey-specific capture behaviour and prey preferences of myrmicophagic and araneophagic jumping spiders (Araneae: Salticidae) 183 CHAPTER 11: Discussion 197 ACKNOWLEDGEMENTS 218 REFERENCES 220 iii LIST OF TABLES (abbreviated captions) Chapter Table Page 2 Habrocestum pulex tested on alternate days (Type 1 t~sts) using living prey. Habrocestum pulex ate ants more often than they ate fruit flies 23 II Two prey presented simultaneously (Type 2 Tests) using living prey. Habrocestum pulex ate ants more often than they ate fruit flies 23 III Two prey presented simultaneously (Type 2 Tests) using living prey. Habrocestum pulex attacked ants more often than they attacked fruit flies 24 IV Habrocestum pulex given second prey while feeding on first prey when using living prey 24 V Habrocestum pulex tested on alternate days (Type 1 tests) using motionless lures. H. pulex chose ant lures more often than it chose fly lures 25 VI Two prey presented simultaneously (Type 2 tests) using motionless lures. Habrocestum pulex chose ant lures more often than it chose fly lures 25 3 Ant-eating salticids studied in the laboratory 32 II Insects used in the laboratory as living prey and motionless lures 33 III Results from Type 1 tests (salticids tested on alternate days) showing that ants were eaten more iv often than other insects. Except for tests in which lures were used, all data are from using living prey 43 IV Results from Type 2 tests (salticids tested with two prey simultaneously) showing that ants were eaten more often than other insects. All data from using living prey 48 V Results from Type 3 tests (salticids given second prey while feeding on first) showing that ants were less often released to attack another insect than vice versa. All data from using living prey 51 4 Prey used in the laboratory for testing Queensland Portia fimbriata 62 II Portia fimbriata tested on alternate days (Type 1 Tests) 76 III Two prey presented to Portia fimbriata simultaneously (Type 2 tests) 77 IV Two prey presented to Portia fimbriata simultaneously (Type 2 tests) 78 V Portia fimbriata given second prey while feeding on first prey (Type 3 tests) 79 VI Preference for certain sizes of prey. Portia fimbriata tested on alternate days (Type 1 tests) 80 VII Preference for certain sizes of prey: Portia fimbriata presented with two prey simultaneously (Type 2 tests). All Portia in these tests ate the prey attacked first. All Portia in these tests were well fed 81 v VIII Preference for certain sizes of prey. Portia fimbriata given second prey while feeding on first prey (Type 3 tests). All Portia in these tests were well fed 82 IX Portia fimbriata females tested on alternate days (Type 1 Tests) by using different taxonomic categories of motionless lures 85 X Two prey presented to Portia fimbriata simultaneously (Type 2 Tests). Different taxonomic categories of motionless lures 86 XI Portia fimbriata tested on alternate days (Type 1 Tests) by using different size classes of motionless lures 87 XII Two lures presented to Portia fimbriata simultaneously (Type 2 Tests). Different sizes of motionless lures 88 5 Prey used in the laboratory for testing Portia labiata from Sri Lanka, P. africana and P. schultzi from Kenya 99 II Portia tested on alternate days (Type 1 Tests) 106 III Two prey presented to Portia simultaneously (Type 2 tests) 107 IV Portia given second prey while feeding on first prey (Type 3 tests) 108 V Poria tested on alternate days (Type 1 Tests) by using different categories of motionless lures 110 VI Two prey presented to Portia simultaneously (Type 2 Tests), different categories of motionless lures 111 vi 6 Spiders and insects used in tests with Scytodes in the laboratory 119 II Inhabitants of 170 different webs of Scytodes in the field 127 III Prey records 1 of Scytodes in the field. Unless noted oth.erwise, Scytodes in its web when observed feeding 129 VI Results of from Type B tests using taxonomic category of prey. Each individual Scytodes tested, in random order, with each of three types of prey. Tests of independence: males and females compared. Tests of independence were also used to compare rate with different types of prey: houseflies compared with Iycosids, houseflies compared with salticids and salticids compared with Iycosids. All prey: small. Salticid, Iycosid and housefly: introduced to cage with the Scytodes's web 133 V Results from Type B tests for Scytodes with three sizes of salticids and insects. Scytodes males and females compared (tests of independence). Capture rates for very small and large prey compared (tests of independence) separately. Sample size for each type of test indicated in parentheses 134 VI Effect of Scytodes female's presence on egg sac survival (see text) 139 7 Salticid species used in tests with Scytodes 147 II Salticid-Scytodes interactions expressed as percentage of tests in which each behaviour occurred 149 vii III Occurrence of individual vibration behaviour in tests during which Portia pursued Scytodes using aggressive mimicry. Occurrence of each behaviour element expressed as numbers of tests during which the behavioural element(s) occurred divided by the total number of tests during which Portia performed aggressive mimicry and multiplied by 100 151 IV Methods used by Portia to pursue Scytodes 153 8 Results from Type 1 tests (Portia labiata tested with one prey at a time on alternate days), showing that brooding Scytodes (prey 1) were attacked and eaten more often than non-brooding Scytodes (prey 2). Both types of prey were in webs 165 II Results from Type 2 tests (two prey presented to Portia labiata simultaneously), showing that brooding Scytodes (prey 1) were attacked and eaten more often than non-brooding Scytodes (prey 2). Both types of prey were in webs 165 III Results from Type 3 tests (Portia labiata given second prey while feeding on first prey), showing that P. labiata dropped non-brooding Scytodes to take brooding Scytodes more often than they dropped brooding Scytodes to take non-brooding Scytodes. Both types of prey were in webs 165 IV Results from Type 1 tests (Portia labiata tested with one lure at a time on alternate days), showing that brooding Scytodes (lure 1) were attacked more often than non-brooding Scytodes (lure 2). Both types of lures were in webs 166 V Results from Type 2 tests (two lures presented to Portia labiata simultaneously), showing that viii brooding Scytodes (lure 1) were attacked more often than non-brooding Scytodes (lure 2). Both types of lures were in webs 166 9 Prey used in the laboratory for rearing Queensland Portia fimbriata 172 II' Summary of life history data for Portia fimbriata reared on three diets: spiders only (SO), insects only (10), and mixed of spiders and insects (MSI). N: No. of individuals entering an instar. Ix: cumulative survivorship. qx: mortality rate 175 III Survival to maturity as a percentage of total No. of first instars reared under each of three diet treatments 176 IV Mean (x) and standard deviation (SD) for body length and 5 carapace measurements (see Fig. 1) of Queensland Portia fimbriata fed on different diets 178 ix LIST OF FIGURE Chapter Figure Page 2 1 Prey preference testing box (PPTB) used to test prey preferences of Habrocestum pulex using living, active prey. a: comb with 10 teeth (round wooden sticks; black in diagram) that could be moved horizontally for pushing P. fimbriata into cells - comb at top with teeth outside tubes; comb at bottom with teeth inside tubes; b: plastic tube; c: cell; d: 2 holes (diameter 8 mm) in the side of a cell; e: removable opaque cardboard screen. See text 15 2 The choice ramp (CR) used for testing prey preference of H. pulex using motionless lure. Test spider walks out of pit near bottom of ramp (circle on right Qf diagram) and up ramp towards motionless lures. See text 18 4 1 Prey preference testing box (PPTB) used to test prey preferences of Portia fimbriata using living prey.