Members of two hunting-wasp families, Pompilidae and Sphecidae, are among the major predators of orb-web spiders. In this study, we collected paralysed spiders from natural nests and trap-nests provisioned by sphecids in an area of Brazilian Atlantic Forest, and compared these data with the composition of species collected by visual searching during one year. Prey preferences were analysed based on the relative abundance of spider species, their size and web characteristics. We also compiled a list of orb-weavers captured by four sphecid genera reported in 40 other studies. A large number of prey was obtained from natural nests of Trypoxylon (Trypargilum) albonigrum in Parque Estadual Intervales, especially species of Eustala, Parawixia, and Araneus (Araneidae). Other prey, stored in trap-nests by T. lactitarse and unidentified hunting-wasp species, included Nephila (Tetragnathidae), Parawixia, Ocrepeira, Mecynogea, Acacesia (Araneidae), and other spider species that were less abundant. All the species that were heavily preyed upon had a relatively lower abundance in our samples of prey availability. The range of body sizes of spiders captured by Trypoxylon in our study area include the size of some abundant orb-weavers always absent in their nests. These results indicate that factors other than abundance in the field and the spider's size influence prey selection or susceptibility to attack. © 2005 Taylor & Francis.393129132933Alves-Costa, C.P., Gonzaga, M.O., Prey capture and spatial distribution of Philoponella vittata (Araneae Uloboridae) in host webs (2001) Ethology, Ecology and Evolution, 13, pp. 239-246Asis, J.D., Tormos, J., Gayubo, S.F., Biological observations on Trypoxylon attenuatum and description of its mature larva and its natural enemy Trichrysis cyanea (Hymenoptera: Sphecidae, Chrysididae) (1994) Journal of the Kansas Entomological Society, 67, pp. 199-207Backhaus, W., Color opponent coding in the visual system of the honeybee (1991) Vision Research, 31, pp. 1381-1397Barber, M.C., Matthews, R.W., Utilization of trap nests by the pipe-organ mud-dauber, Trypargilum politum (Hymenoptera, Sphecidae) (1979) Annals of the Entomological Society of America, 72, pp. 260-262Beaver, D.L., Baldwin, P.H., Ecological overlap and problem of competition and sympatry in the western and Hammond's flycatchers (1975) Condor, 77, pp. 1-13Berman, J.D., Levi, H.W., The orb weaver genus Neoscona in North America (Araneae: Araneidae) (1971) Bulletin of the Museum of Comparative Zoology, 141, pp. 465-500Blackledge, T.A., Signal conflict in spider webs driven by predators and prey (1998) Proceedings of the Royal Society of London B, 265, pp. 1991-1996Blackledge, T.A., Coddington, J.A., Gillespie, R.G., Are three-dimensional spider webs defensive adaptations? (2003) Ecology Letters, 6, pp. 13-18Blackledge, T.A., Picket, K.M., Predatory interactions between mud-dauber wasps (Hymenoptera, Sphecidae) and Argiope (Araneae, Araneidae) in captivity (2000) Journal of Arachnology, 28, pp. 211-216Blackledge, T.A., Wenzel, J.W., Silk mediated defense by an orb web spider against predatory mud-dauber wasps (2001) Behaviour, 138, pp. 155-171Bohart, R.M., Mencke, A.S., (1976) Sphecid Wasps of the World, 695p. , Berkeley: University of California PressBranson, B.A., Spiders of the University of Oklahoma Biological Station, Marshall County, Oklahoma, with observations on species used by muddaubers as larval food, and a review of the species known from Oklahoma (1966) Southwestern Naturalist, 11, pp. 338-371Briscoe, A.D., Chittka, L., The evolution of color vision in insects (2001) Annual Review of Entomology, 46, pp. 471-510Bruch, C., Apuntes sobre costumbres de Trypoxylon palliditarse Sauss (Hymenoptera) (1932) Anales de la Sociedad Cientifica Argentina, 114, pp. 49-61Camillo, E., Bionomics of Trypoxylon (Trypargilum) antropovi and Trypoxylon (Trypargilum) aestivale (Hymenoptera, Sphecidae) (1999) Iheringia Serie Zoologia, 87, pp. 29-36Camillo, E., The natural history of the mud-dauber wasp Sceliphron fistularium (Hymenoptera: Sphecidae) in southeastern Brazil (2002) Revista de Biologia Tropical, 50, pp. 127-134Camillo, E., Brescovit, A.D., Spiders (Araneae) captured by Trypoxylon (Trypargilum) lactitarse (Hymenoptera: Sphecidae) in southeastern Brazil (1999) Revista de Biologia Tropical, 47, pp. 151-162Camillo, E., Brescovit, A.D., Aspectos biológicos de Trypoxylon (Trypargilum) lactitarse Saussure e Trypoxylon (Trypargilum) rogenhoferi Kohl (Hymenoptera: Sphecidae) em ninhos-armadilhas, com especial referência a suas presas (1999) Anais Da Sociedade Entomológica Do Brasil, 28, pp. 251-262Camillo, E., Garofalo, C.A., Muccillo, G., Serrano, J.C., Biological observations on Trypoxylon (Trypargilum) lactitarse Saussure in southeastern Brazil (Hymenoptera, Sphecidae) (1993) Revista Brasileira de Entomologia, 37, pp. 769-778Camillo, E., Garofalo, C.A., Serrano, J.C., Biological observation of Trypoxylon (Trypargilum) rogenhoferi Kohl (Hymenoptera: Sphecidae) (1994) Anais Da Sociedade Entomologica Do Brasil, 23, pp. 299-310Cloudsley-Thompson, J.L., A review of the anti-predator devices of spiders (1995) Bulletin of the British Arachnological Society, 10, pp. 81-96Conley, M.R., Predation versus resource limitation in survival of adult burrowing wolf spiders (Araneae: Lycosidae) (1985) Oecologia, 67, pp. 71-75Coville, R.E., Biological observations on Trypoxylon (Trypargilum) orizabense Richards in Arizona (Hymenoptera: Sphecidae) (1979) Journal of the Kansas Entomological Society, 52, pp. 613-620Coville, R.E., Wasps of the genus Trypoxylon subgenus Trypargilum in North America (1982) University of California Publications on Entomology, 97, pp. 1-147Coville, R.E., Spider prey of Trypoxylon tridentatum (Hymenoptera: Sphecidae) from Arizona and California (1986) Pan-Pacific Entomologist, 62, pp. 119-120Coville, R.E., Spider-hunting sphecid wasps (1987) Ecophysiology of Spiders, pp. 309-318. , Nentwig W, editor. Berlin: Springer-VerlagCoville, R.E., Coville, P.L., Nesting biology and male-behavior of Trypoxylon tenoctitlan (Trypargilum) in Costa-Rica (Hymenoptera, Sphecidae) (1980) Annals of the Entomological Society of America, 73, pp. 110-119Coville, R.E., Griswold, C., Coville, P.L., Observations on the nesting biology and behavior of Trypoxylon (Trypargilum) vagulum (Hymenoptera: Sphecidae) in Costa Rica (2000) Pan-Pacific Entomologist, 76, pp. 28-48Cross, E.A., Stith, M.G., Bauman, T.R., Bionomics of organ-pipe mud-dauber, Trypoxylon politum (Hymenoptera, Sphecoidea) (1975) Annals of the Entomological Society of America, 68, pp. 901-916Danks, H.V., Biology of some stem-nesting aculeate Hymenoptera (1970) Transactions of the Royal Entomological Society of London, 122, pp. 323-395Dorris, P.R., Spiders collected from mud-dauber nests in Mississippi (1970) Journal of the Kansas Entomological Society, 43, pp. 10-11Eberhard, W.G., The predatory behavior of two wasps, Agenoideus humilis and Sceliphron caementarium, on the orb weaving spider, Araneus cornutus (1970) Psyche, 77, pp. 243-251Edmunds, J., Wasp predation on orb web spiders (Araneidae) in Ghana (1990) Acta Zoologica Fennica, 190, pp. 117-122Elgar, M.A., Jebb, M., Nest provisioning in the mud-dauber wasp Sceliphron laetum (F. Smith): Body mass and taxa specific prey selection (1999) Behaviour, 136, pp. 147-159Enders, F., Selection of habitat by the spider Argiope aurantia (Araneidae) (1972) American Midland Naturalist, 90, pp. 47-55Endo, T., Endo, A., Prey selection by a spider wasp, Batozonellus lacerticida (Hymenoptera: Pompilidae): Effects of seasonal variation in prey species, size and density (1994) Ecological Research, 9, pp. 225-235Evans, H.E., Notes on the nesting behavior of Pisonopsis clypeata and Belomicrus forbesii (Hymenoptera, Sphecidae) (1969) Journal of the Kansas Entomological Society, 42, pp. 117-125Freeman, B.E., Johnston, B., The biology in Jamaica of the adults of the Sphecid wasp, Sceliphron assimile Dahlbom (1978) Ecological Entomology, 3, pp. 39-52Genaro, J.A., Sobre la nidificación de Sceliphron caementarium y primer registro de Trypoxylon texense para Puerto Rico (Hymenoptera: Sphecidae) (1996) Caribbean Journal of Science, 32, pp. 243-244Genaro, J.A., Alayón, G., Las presas (Araneae) de Trypoxylon (Trypargilum) subimpressum (Hymenoptera: Sphecidae) en Cuba (1994) Revista de Biologia Tropical, 42, pp. 353-356Genaro, J.A., Sanchez, C.S., Garcia, G.A., Notas sobre la conducta de nidificacion de Trypoxylon (Trypargilum) subimpressum Smith (Hymenoptera: Sphecidae) (1989) Caribbean Journal of Sciences, 25, pp. 228-229Gonzaga, M.O., Vasconcellos-Neto, J., Testing the functions of detritus stabilimenta in webs of Cyclosa fililineata and Cyclosa morretes (Araneae: Araneidae): Do they attract prey or reduce the risk of predation? (2005) Ethology, 111, pp. 479-491Gonzales-Bustamante, L., Micrathena spp. (Araneida: Araneidae), presa preferida por Sceliphron sp. (Hymenoptera: Sphecidae) en Pilcopata (Cusco) (1994) Revista Peruana de Entomologia, 36, p. 22Gwynne, D.T., Dodson, G.N., Nonrandom provisioning by the digger wasp, Palmodes laeviventris (Hymenoptera: Sphecidae) (1983) Annals of the Entomological Society of America, 76, pp. 434-436Hanson, P., Menke, A.S., The sphecid wasps (Sphecidae) (1995) The Hymenoptera of Costa Rica, pp. 621-649. , Hanson PE, Gauld ID, editors. Oxford: Oxford University PressHenschel, J.R., Predation on social and solitary individuals of the spider Stegodyphus dumicola (Araneae, Eresidae) (1998) Journal of Arachnology, 26, pp. 61-69Herberstein, M.E., Heiling, A.M., Positioning at the hub: Does it matter on which side of the web orb-web spiders sit? (2001) Journal of Zoology, 255, pp. 157-163Hódar, J.A., The use of regression equations for estimation of arthropod biomass in ecological studies (1996) Acta Oecologica, 17, pp. 421-433Hook, A.W., Notes on the nesting and mating behavior of Trypoxylon (Trypargilum) spinosum (Hymenoptera, Sphecidae) (1984) Journal of the Kansas Entomological Society, 57, pp. 534-535Hormiga, G., Scharff, N., Coddington, J.A., The phylogentic basis of sexual size dimorphism in orb-weaving spiders (Araneae, Orbiculariae) (2000) Systematic Biology, 49, pp. 435-462Horner, N.V., Klein, J.H., Spider prey of two mud dauber wasp species in Comanche County, Oklahoma (Hymenoptera, Sphecidae) (1979) Environmental Entomology, 8, pp. 30-31Jiménez, M.L., Servin, R., Tejas, A., Aguilar, R., La composición de presas de la avispa lodera Sceliphron jamaicense Lucae en la region del Cabo, México (1992) Southwestern Entomologist, 17, pp. 169-180Jiménez, M.L., Tejas, A., Las aranas presa de la avispa lodera Trypoxylon (Trypargilum) tridentatum tridentatum en Baja California Sur, Mexico (1994) Southwestern Entomologist, 19, pp. 173-180Kaston, B.J., Notes on pompilid wasps that do not dig burrows to bury their spider prey (1959) Bulletin of the Brooklyn Entomological Society, 54, pp. 103-113Krombein, K.V., Behavioral and life-history notes on three Floridian solitary wasps (Hymenoptera: Sphecidae) (1970) Smithsonian Contributions to Zoology, 46, pp. 1-26Kurczewski, F.E., Spofford, M.G., Observations on the nesting behaviors of Tachytes parvus Fox and T. obductus Fox (Hymenoptera: Sphecidae) (1986) Proceedings of the Entomological Society of Washington, 88, pp. 13-24Laing, D.J., The prey and predation behaviour of the wasp Pison morosum (Hymenoptera: Sphecidae) (1988) New Zealand Entomologist, 11, pp. 37-42Levi, H.W., The American orb-weaver genera Cyclosa, Metazygia and Eustala North of Mexico (Araneae: Araneidae) (1977) Bulletin of the Museum of Comparative Zoology, 148, pp. 61-127Lin, C.S., Biology of Trypargilum spinosum, with notes on T. texense and T. politum at Lake Texoma (Hymenoptera: Sphecidae: Trypoxyloninae) (1969) Wasmann Journal of Biology, 27, pp. 125-133Lunau, K., Wacht, S., Chittka, L., Colour choices of naïve bumble bees and their implications for colour perception (1996) Journal of Comparative Physiology A, 178, pp. 477-489Matthews, R.W., Biology of a new Trypoxylon that utilizes nests of Microstigmus in Costa Rica (Hymenoptera, Sphecidae) (1983) Pan-Pacific Entomologist, 59, pp. 152-162McQueen, D.J., Field studies of growth, reproduction, and mortality in the burrowing wolf spider Geolycosa domifex (Hancock) (1978) Canadian Journal of Zoology, 56, pp. 2037-2049Medler, J.T., Biology of Trypoxylon in trap nests in Wisconsin (Hymenoptera: Sphecidae) (1967) American Midland Naturalist, 78, pp. 344-358Muma, M.H., Jeffers, W.F., Studies of the spider prey of several mud-dauber wasps (1945) Annals of the Entomological Society of America, 38, pp. 245-255O'Brien, M.F., Trypargilum tridentatum (Packard) in trap nests in Oregon (Hymenoptera: Sphecidae: Trypoxylinae) (1982) Pan-Pacific Entomologist, 58, pp. 288-290O'Brien, M.F., Kurczewski, F.E., Ethology and overwintering of Podalonia luctuosa (Hymenoptera: Sphecidae) (1982) Great Lakes Entomologist, 15, pp. 261-275O'Neill, K.M., Egg size, prey size, and sexual size dimorphism in digger wasps (Hymenoptera: Sphecidae) (1985) Canadian Journal of Zoology, 63, pp. 2187-2193O'Neill, K.M., The male mating strategy of the ant Formica subpolita Mayr (Hymenoptera: Formicidae): Swarming, mating, and predation risk (1994) Psyche, 101, pp. 93-108O'Neill, K.M., (2001) Solitary Wasps: Behavior and Natural History, p. 406. , Ithaca (NY): Cornell University PressPolis, G.A., Hurd, S.D., Jackson, C.T., Sanchez-Pinero, F., Multifactor population limitation: Variable spatial and temporal control of spiders on Gulf of California Island (1998) Ecology, 79, pp. 490-502Rau, P., Field studies in the behavior of the non-social wasps (1928) Transactions of the Academy of Sciences, 25, pp. 325-489. , St LouisRau, P., The prey and hunting habits of the wasp, Trypoxylon politum Say (1944) Entomological News, 55, pp. 9-10Rayor, L.S., Attack strategies of predatory wasps (Hymenoptera: PompilidaeSphecidae) on colonial orb web-building spiders (Araneidae: Metepeira incrassata) (1996) Journal of the Kansas Entomological Society, 69, pp. 67-75Rehnberg, B.G., Selection of spider prey by Trypoxylon politum (Say) (Hymenoptera: Sphecidae) (1987) Canadian Entomologist, 119, pp. 189-194Roble, S.M., Submergent capture of Dolomedes triton (Araneae, Pisauridae) by Anoplius depressipes (Hymenoptera, Pompilidae) (1985) Journal of Arachnology, 13, p. 392Rogers, L.E., Buschom, R.L., Watson, C.R., Length-weight relationships of scrub-steppe invertebrates (1977) Annals of the Entomological Society of America, 70, pp. 51-53Sample, B.E., Cooper, R.J., Greer, R.D., Whitmore, R.C., Estimation of insect biomass by length and width (1993) American Midland Naturalist, 129, pp. 234-240Scharff, N., Coddington, J.A., Griswold, C.E., Hormiga, G., Bjørn, P.P., When to quit? Estimating spider species richness in a northern European deciduous forest (2003) Journal of Arachnology, 31, pp. 246-273Schoener, T.W., Length-weight regressions in tropical and temperate forest-understory insects (1980) Annals of the Entomological Society of America, 73, pp. 106-109Silva, D., Species composition and community structure of Peruvian rainforest spiders: A case study from a seasonally inundated forest along the Samiria river (1996) Revue Suisse de Zoologie Volume Hors Série, pp. 597-610Sørensen, L.L., Stratification of the spider fauna in a Tanzanian forest (2003) Arthropods of Tropical Forests - Spatio Temporal Dynamics and Resource Use in the Canopy, pp. 92-103. , Basset Y, Novotny V, Miller SE, Kitching RL, editors. Cambridge: Cambridge University PressSørensen, L.L., Coddington, J.A., Scharff, N., Inventoring and estimating subcanopy spider diversity using semiquantitative sampling methods in an Afromontane forest (2002) Environmental Entomology, 31, pp. 319-330Uetz, G.W., Hieber, C.S., Group size and predation risk in colonial web-building spiders: Analysis of attack abatement mechanisms (1994) Behavioral Ecology, 5, pp. 326-333Volkova, T., Matthews, R.W., Barber, M.C., Spider prey of two mud dauber wasps (Hymenoptera: Sphecidae) nesting in Georgia's Okefenokee swamp (1999) Journal of Entomological Sciences, 34, pp. 322-327Ward, G.L., Growth of Chalybion zimmermanni Dahlbom in captivity (Hymenoptera: Sphecidae) (1970) Proceedings of the Indian Academy of Sciences, Animal Sciences, 79, pp. 231-233Ward, D., Lubin, Y., Habitat selection and the life history of a desert spider Stegodyphus lineatus (Eresidae) (1993) Journal of Animal Ecology, 62, pp. 353-363Wasbauer, M.S., Pompilidae (1995) The Hymenoptera of Costa Rica, pp. 522-539. , Hanson PE, Gauld ID, editors. Oxford: Oxford University PressZar, J.H., (1999) Biostatistical Analysis, 663p. , Upper Saddle River (NJ): Prentice Hall