BIONOZOS OF SOIL] STM4T2STING AOULIM HILLOOPTERA. by HUGH VICTOR DAMS, B.Sc. A Thesis submitted for the degree of Doctor of Philosophy in the Faculty of Science of the University of London Imperial College Field Station, Silwood Park, Sunninghill, September 1968 Ascut, Berkshire 2. ABSTRhCT Studios wore wade on the biolo:17 of a number of stem-nesting, aculeato Hymenoptera and their parasites, in particular on those nesting in Rubus fruticosus aai. (bramble), usirw, especially - as a means of obtaining nest material - trap-nests of bundles of stems of this plant. General observations and laboratory experiments 7ielded inform- ation for various species on nest architecture, prey, voltinism, dat- es of emergence, sex ratio, suporeedure, parwato/host relationships and other aspects of general aculeato bioloy. A laboratory culture of one species was established. The observed nest mortalities from various causes wore tabulated for each species. The total nest mortality was similar for most species, and indicated that the surv- ival of aculeate pro;7eny was hi;h compared to most insect species, but that the resultini; potential of a given female to produce large nufflbers of progeny was offset by the labour involved in makin;, nests and by competition for the limited number of available nestin..-sites. Population estimates of certain species wore also made, both by a combination of mark-recapture and trap-nest techniques, and by sam- pling the bramble bushes of the natural habitat. Some factors affect- ing the utilisation of nesting sites were also studied. Populations wore shown to be generally very low, and differences in the population size and in the dispersal of different species were detected. A key to the nests of British Rubus-nesting; aculeates and their commoner parasites was constructed. 3. CONTENTS page INTRODUCTION 7 NOIENOLATURE 10 PART A. ITTE BIOLOGY OF S0LiE STILL-Yr:WING ACULLATES 11 I. Introduction 11 TI..Zxporimental techniques - 12 1 . Trap-nesting 12 2. Treatwont of collected nests 14. 3. Preservation of food stores 15 4. Presorvation of developmental stages 16 5. Exporimonts on development 17 6. Laboratory culture 18 III.Biology of aculoato spccios 22 Sphocidao: 1. Comonus lothifor Shuck. 22 Literature, 22; General, 25; Habitat, 25; nest architecture and construction, 25; Stocking activity, 29 ; Prey, 30; Dov- olopmont and voltinism, 4.1; Emer-onco and sex ratio, 44; Mating, 49; Adult longevity and fecundity,51 ; Suporceduro and competition, 53; Parasites, 55; Summary of nest data; mortality factors, 56 2.Comonus shuckardi Koraw. 61 Literature, 61; Gonora3jrabitat,-63; nest architecture, 63; Pray, 64; Development and voltinism, 64; Emunience and sex ratio, 64; tlating, 66; Suporceduro, 66; Parasites, 66; Summary of nest data; mortality factors, 66 3.Passaloccus zracilis (Curt.) 68 Literature, 68; General; habitat, 72; Nest architecture, 72; Prey, 74; Emergence and sex ratio, 74; Supercodure, 76; Parasitos, 76; Summary of nest data; mortality factors, 77 4.Passaloccus insi6nis (v.d.L.) 79 Literature, 79; General summary of observations, 81; Prey, 82 5.Stipmus s ols kyi Koraw. 84 Literature, 84; General sum,ary of observations, 85 6.Spilomona troF,lody-tos agg. 87 Litoraturo, 87; General; habitat, 89; Nest architocture, 90; Pray, 91; Cocoon, 91; Emorgence and sox ratio, 91; dating, 92 ; Adult lonEovity, 93; Suporceduro, 93; Parasitos, 94; Summary of nest data; mortality factors, 94. 7.Psenulus concolor (Dahlb.) 98 Literature, 98; General, habitat, 99; Nest architecturo,100; Pray, 1005 Emor4„ence,101; hhtinE1 101; Suporceduro, 102; Summary of nest data; mortality factors1 102 8.Psenulus schoncki (Tourn.) 104 Literature, 104; Gonoral; habitat,105; Nest architocture,105; Prey, 106; Cocoon, 106; Emorgence and sex ratios 108; Parasites, 108 ; Summary of nest data; mortality factors, 108 9.Trypoxylon fi;ulus (Linn.) 1110 10.Trypoxylon atIonuatum Smith LiT,oraturo, 110; General; habitat, 114.; Nest architecture, 115; if. page Stocking activity, 116; Prey, 118; Development and voltinism, 118 ; Emor&onco and sex ratio, 124; Adult longevity, 124; Suporcoduro and competition, 125; Parasites, 125; Summary of nest data; mortality factors, 126 11.Corynopus coarctatus (Scop.) 132 Literature, 132; General; habitat, 136; Nest architecture, 136; Prey, 137; Emergence, sex ratio, voltinism and adult longevity, 146; Suporcoduro, 14.7; Parasitos, 1485 Summary of nest data; mortality factors, 149 12.Rhopalum clavipos (Linn.) 152 Litoraturo0 152; General; habitat, 157; Nest architecture, 157; Prey, 158; Voltinism, omorgenco, adult longevity and sex ratio, 158; Supercedure, 1635 Parasites, 163; Summary of nest data; mortality factors, 164 13.Coolocrabro capitosus (Shuck.) 167 Literature, 167; General observations, 169; Prey, 1 69;Parasites, 171 ; Summary of nest data; mortality factors, 171 Eum -nidao : 14. Odyilerus laovipos Shuck. 173 Literature, 1735 General ssuaumary of observations, 176 15. nicrodynorus oxilis (H.-8.) 177 Literature, 177; General summary of observations, 178 Colletidac: 16. Prosopis brovicornis (Nyl.) 179 Literature, 179; General; hag...Ta,181; Nest architecture, 184 Larval food, 1835 Development and voltinism, 184 Morpholo7y of propupa, 186; Emorgonco and sox ratio, 18958uperceduro, 189; Parasites, 190; Summary of nest data; mortality factors, 190 17. Proso-As communis (Nyl.) 195 Litoraturo, 195; General; habitat, 197; Nest architecture; larval food, 198; Morphology of prepupa, 198; Summary of nest data, 199 Mogachilidao: 18. Mogachilo versicolor 3 ith 200 Literature, 200; General summary of observations, 200; Morphology of propupa, 201 19. Osmia loucomolana (Kirby) 204 Literature, 2045 General summary of observations, 207 IV. Biology of aculeato parasites 209 Ichncumonidao: 1. Porithous divinator TRossi) 209 Literature, 209; General, 210; i.ethod of parasitism, 211; Devolopment and voltinism, 211; NerpholOLfy of mature larva,213 Emergence and sox ratio, 216; :Latina', 217; Adult longevity, 218 ; Hosts, 219; General summary and host relationship, 220 2. Hoplocryptus signatorius (Fab.) 222 Litoraturo, 222; General, 223; Method of patasitism, 223; Develop- mont, 223; Morphology of mature larva, 224; Emorgonce and sex ratio, 224; gating, 227; Adult longevity, 228; Hosts, 22 General summary and host relationship, 230 3, Noorhacodos onslini (Ru&chka) 231 Literature, 231; General; stage parasitised, 231; Cocoon, 231; Morphology of mature larva, 23 Emori,once and sox ratio, 232 4. Ischnurgops fragilis (Gray.) 236 Literature, 236; General observations, 236; .6forpholoy of mature larva, 237 5. page Chrysididao: 5. Omalus auratus (Linn.) 239 Literature, 239; General observations, 240; Voltinism, 240 Hosts, 241 6. Chrjrsis cyanea (Linn.) 243 Literature, 243; General summary of observations, 243 Chalcidoidoa: 7. Eurytoma sp. 246 Litoraturo, 246; General; method of parasitism, 247; Development and voltinism, 247; Morphology of mature larva, 247; Emergence and sex ratio, 249; Hosts, 249; Genorai. summary and host relationship, 251 8. Diomorus armatus (Boh.) 252 Literature, 252; General; method of parasitism, 252; Morphology of mature larva, 255; EMer,:.encos and sex ratio, 255; Hosts, 257; General suarmary and host relationship, 257 V. Aculeate nest predators 258 VI.General discussion 260 VII.Summary 271 Part B. hEASUREMENT OF RUBUS-NESTIM ACULEAT3 POPULATIONS 275 I.Introduction 275 II.ilark-recapture estimates 277 Methods 277 Results 278 Discussion 283 Conclusions 286 III. Bramble sample estimates 287 Methods 287 1.Survey of bramble bushes 287 2.Superficial search of bushes 287 3.Volume-sampling of bushes 287 Results 288 1.Survey of bramble bushes 288 2.Suporficial search of bushes 299 3.Volume-sampling of bushes 305 Population ostima-bos and discussion 314 Conclusions 318 IV. Utilisation of nesting;-sitos 320 Introduction 320 Methods 320 1.The effects of vegetation cover and shade 320 2.Altornativo nesting-sites 321 3.Species composition in other areas 321 Results 321 1.The effects of vegetation cover and shade 321 2.Alternative nesting-sites 322 3.Species composition in other areas 327 Conclusions 330 6. page V.General Discussion and conclusions 331 VI.Suaaary 336 PART C. KEY TO MI NESTS OF BRITISH ACUILEATE HYYLZOFTERA IN RUBUS-ST:LS, AND THI2IR COAsiONM1 PARASITES 339 Introduction 339 Key 340 ACENCOLEUX1EifINTS 352 APPENDIX I - recorded parasites of aculeato species 354 REFERENCES 366 7 INTRODUCTION The aculeate gymonoptera have in the past prompted a number of studies because of the relative complexity of their behaviour, particularly in the social species. The solitary bees and wasps have also attracted attention from a number of entomologists, particularly in Europe, in North Lmerica and more recently in Japan. Consequently the general life-history of these solitary species is well known; suitable crevices are sought out, or excavated, by the female bee or wasp, and one or several cells constructed, each cell typically containing a store of food - pollen or honey in the bees, and paralysed invertebrate prey in the wasps - and a single egg, from which a larva hatches to feed on the food store. Many such species nest in the ground, sandy soils forming the most typical nesting site, but others utilise rotten wood, plant stems or other sites for the construction of their cells. The species discussed in the present work are those which nest in plant stems, and in particular those nesting in the pith of dead stems of Rubus fruticosus agg. (bramble), a plant chosen for its general abundance in England; for its abundance