Parasitoid-induced Mortality Of Araneus Omnicolor (araneae, Araneidae) By Hymenoepimecis Sp. (hymenoptera, Ichneumonidae) In Southeastern Brazil

All species included in the Polysphincta genus-group develop as ectophagous parasitoids of active spiders, killing their hosts prior to pupation. However, little information regarding natural history and ovipositing behavior of most species are available. In this study we inspected 85 webs of Araneus omnicolor to evaluate the frequency of parasitism and host size preferences of the wasp Hymenoepimecis sp. We also described the web characteristics of normal and parasitized spiders and the wasp ovipositing behavior. About 41% of the adult females of A. omnicolor inspected were parasitized. The highest incidence of parasitism was observed among relatively small females while no egg or larva was found in large individuals. Araneus omnicolor builds a strong web composed of an orb and barrier threads, where the spider rests within a curled leaf. The parasitoid larva builds its cocoon within this refuge, and modified cocoon webs were not observed. The ovipositing behavior of Hymenoepimecis sp. was very similar to that of Hymenoepimecis argyraphaga parasitizing Leucauge argyra, including the position of the sting, the killing of a previously attached larva, and the expelling of the egg from the base of the ovipositor. © 2006 Springer-Verlag.943223227Blackledge, T.A., Coddington, J.A., Gillespie, R.G., Are three-dimensional spider webs defensive adaptations? (2003) Ecol Lett, 6, pp. 13-18Dubois, J., Rollard, C., Villemant, C., Gauld, I.D., The phylogenetic position of parasitoids of spiders within Pimplinae (Hymenoptera, Ichneumonidae) (2002) Proceedings of the 20th European Colloquium of Arachnology, pp. 27-35. , Samu F, Szinetár Cs eds, Plant Protection Institute and Berzsenyi College, Budapest, ppEberhard, W.G., The natural history and behavior of Hymenoepimecis argyraphaga (Hymenoptera: Ichneumonidae) a parasitoid of Plesiometa argyra (Araneae: Tetragnathidae) (2000) J Hymenopt Res, 9, pp. 220-240Eberhard, W.G., Spider manipulation by a wasp larva (2000) Nature, 406, pp. 255-256Eberhard, W.G., Under the influence: Webs and building behavior of Plesiometa argyra (Araneae, Tetragnathidae) when parasitized by Hymenoepimecis argyraphaga (Hymenoptera, Ichneumonidae) (2001) J Arachnol, 29, pp. 354-366Fincke, O.M., Higgins, L., Rojas, E., Parasitism of Nephila clavipes (Araneae, Tetragnathidae) by an ichneumonid (Hymenoptera, Polysphinctini) in Panama (1990) J Arachnol, 18, pp. 321-329Fitton, M.G., Shaw, M.R., Austin, A.D., The Hymenoptera associated with spiders in Europe (1987) Zool J Linn Soc, 90, pp. 65-93Gauld, I., The re-definition of pimpline genus Hymenoepimecis (Hymenoptera: Ichneumonidae) with a description of a plesiomorphic new Costa Rican species (2000) J Hymenopt Res, 9, pp. 213-219Gauld, I.D., Dubois, J., Phylogeny of the Polysphincta group of genera (Hymenoptera: IchneumonidaePimplinae): a taxonomic revision of spider ectoparasitoids (2006) Syst Entomol, 31 (3), pp. 529-564. , DOI 10.1111/j.1365-3113.2006.00334.xLevi, H.W., The Neotropical and Mexican species of the orbweaver genera Araneus, Dubiepeira, and Aculepeira (Araneae: Araneidae) (1991) Bull Mus Comp Zool, 152, pp. 167-315Rehnberg, B.G., Selection of the spider prey by Trypoxylon politum (Say) (Hymenoptera: Sphecidae) (1987) Can Entomol, 119, pp. 189-194Tolbert, W.W., Predator avoidance behavior and web defensive structures in the orb weavers Argiope aurantia and Argiope trifasciata (Araneae, Araneidae) (1975) Psyche, 82, pp. 29-52Townes, H., The genera of Ichneumonidae, part 1 (1969) Mem Am Entomol Inst, 11, pp. 1-300Wahl, D.B., Gauld, I.D., The cladistics and higher classification of the Pimpliformes (Hymenoptera: Ichneumonidae) (1998) Syst Entomol, 23, pp. 265-29

Nesting Characteristics And Spiders (arachnida: Araneae) Captured By Auplopus Argutus (hymenoptera: Pompilidae) In An Area Of Atlantic Forest In Southeastern Brazil

All pompilids use spiders to provide food for their larvae, and these hunting wasps can be responsible for a significant impact on the populations of their prey. Data on spider species captured, characteristics of the nests, fecundity and seasonal variation in reproductive frequency, however, are not available for most pompilid species. Here we describe the nesting behavior of Auplopus argutus based on 108 nests from an area of Atlantic Forest in southeastern Brazil. The wasps deposited each spider in a clay vessel, constructed within the bamboo cylinders used as traps. In each trap we found from 1 to 19 vessels, totalizing 508 provisioned cells. From these, 84 contained spiders in good conditions of conservation, allowing identification. The females of A. argutus provisioned their nests with 21 spider species, belonging to eight families: Anyphaenidae, Corinnidae, Ctenidae, Miturgidae, Salticidae, Senoculidae, Sparassidae and Zoridae. Almost all the spiders collected in the nests had their legs amputated and were equivalent or greater in size than the mean body size of the wasps.1173281287Cambra, R.A.T., Quintero, D.A., Miranda, R., Presas, comportamiento de anidación y nuevos registros de distribución en pompílidos neotropicales (Hymenoptera: Pompilidae) (2004) Tecnociencia, 6, pp. 95-109Dreisbach, R.R., New species of spider wasps, genus Auplopus, from the Americas South of the United States. (Hymenoptera: Psammocharidae) (1963) Proceedings of the United States National Museum, 114, pp. 137-211Fernández, F., Avispas cazadoras de arañas (Hymenoptera: Pompilidae) de la región Neotropical Biota Colombiana, 1, pp. 3-24Kimsey, L.S., Notes on the biology of some Panamanian Pompilidae with a description of communal nest (Hymenoptera) (1980) Pan-Pacific Entomologist, 56, pp. 98-100Klein, A.M., Steffan-Dewenter, I., Tscharntke, T., Foraging trip duration and density of megachilid bees, eumenid wasps and pompilid wasps in tropical agroforestry systems (2004) Journal of Animal Ecology, 73, pp. 517-525Kursczewski, F.E., Observations on the nesting behavior of Auplopus caerulescens subcorticalis and other Auplopodini (Hymenoptera: Pompilidae) (1989) Great Lakes Entomologist, 22, pp. 71-74Kursczewski, F.E., Kursczewski, E.J., Host records for some North American Pompilidae (Hymenoptera) with a discussion of factors in prey selection (1968) Journal of the Kansas Entomological Society, 41, pp. 1-33Martins, R.P., (1991) Biologia e Comportamento de Comunidades de Vespas Escavadoras (Hymenoptera: Aculeata), , Ph.D. Thesis. Universidade Estadual de Campinas, Campinas, Sao Paulo, Brazil. 116 ppO'Neill, K.M., (2001) Solitary Wasps: Behavior and Natural History, , Cornell University Press, Ithaca, New York, U.S.A. 406 ppRayor, 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 (SUPPL.), pp. 67-75Rehnberg, B.G., Selection of spider prey by Trypoxylon politum (Say) (Hymenoptera: Sphecidae) (1987) Canadian Entomologist, 119, pp. 189-194Wasbauer, M.S., Pompilidae (1995) The Hymenoptera of Costa Rica, pp. 522-539. , P.E. Hanson and I.D. Gauld (Editors). Oxford University Press, Oxford, United Kingdom. 920 ppWcislo, W.T., West-Eberhard, M.J., Eberhard, W.G., Natural history and behavior of a primitively social wasp, Auplopus semialatus, and its parasite, Irenangelus eberhardi (Hymenopter: Pompilidae) (1988) Journal of Insect Behavior, 1, pp. 247-260Zanette, L.R.S., Soares, L.A., Pimenta, H.C., Gonçalves, A.M., Martins, R.P., Nesting biology and sex ratios of Auplopus militaris (Lynch-Arribalzaga 1873) (Hymenoptera Pompilidae) (2004) Tropical Zoology, 17, pp. 145-15

On The Sticky Cobwebs Of Two Theridiid Spiders (araneae: Theridiidae)

In this study we describe and illustrate a new species, Chrysso intervales n. sp., based on males and females collected in Parque Estadual Intervales, an area of Atlantic Forest in the State of São Paulo, Brazil. We present data on habitat selection, web architecture, thread adhesiveness, diet, and mortality due to fungi for both Chrysso intervales and the sympatric species, Helvibis longicauda . Both species build webs on vegetation close to river margins, but they were not found in forest sites away from these shaded and extremely humid corridors. The webs of both species are entirely composed of viscid silk lines, occupying the space between two or more large leaves. The construction of this web type by Helvibis and Chrysso , and the large amount of viscid droplets in their threads, indicate that the investment in adhesive components in theridiids may be dependent on the ambient conditions. We suggest that the costs of maintaining viscid silk lines in humid areas may be relatively low, explaining the habitat restriction observed in the species studied. By selecting humid habitats, however, these spiders are susceptible to attacks by fungi. The webs constructed by both species intercepted mostly Diptera, especially tipulids, but H. longicauda was also observed consuming a wide variety of prey types. © 2006 Taylor & Francis.4005/06/15293306Agnarsson, I., Morphological phylogeny of cobweb spiders and their relatives (Araneae, Araneoidea, Theridiidae) (2004) Zoological Journal of the Linnean Society, 141, pp. 447-626Arnedo, M.A., Coddington, J., Agnarsson, I., Gillespie, R.G., From a comb to a tree: Phylogenetic relationships of the comb-footed spiders (Araneae, Theridiidae) inferred from nuclear and mitochondrial genes (2004) Molecular Phylogenetics and Evolution, 31, pp. 225-245Benjamin, S.P., Zschokke, S., Untangling the tangle-web: Web construction behavior of the comb-footed spider Steatoda triangulosa and comments on phylogenetic implications (Araneae: Theridiidae) (2002) Journal of Insect Behavior, 15, pp. 791-809Benjamin, S.P., Zschokke, S., Webs of theridiid spiders: Construction, structure and evolution (2003) Biological Journal of the Linnean Society, 78, pp. 293-305Blackledge, T.A., Coddington, J.A., Gillespie, R.G., Are three-dimensional spider webs defensive adaptations? (2003) Ecology Letters, 6, pp. 13-18Borror, D.J., Triplehorn, C.A., Johnson, N.F., (1989) An Introduction to the Study of Insects, 875p. , Philadelphia: Saunders College PublishingEberhard, W.G., Argyrodes attenuatus: A web that is not a snare (1979) Psyche, 86, pp. 407-413Eberhard, W.G., Function and phylogeny of spider webs (1990) Annual Review of Ecology and Systematics, 21, pp. 341-372Eberhard, W.G., Trolling for water striders: Active searching for prey and the evolution of reduced webs in the spider Wendilgarda sp. (Araneae, Theridiosomatidae) (2001) Journal of Natural History, 35, pp. 229-251Edmonds, D.T., Vollrath, F., The contribution of atmospheric water vapour to the formation and efficiency of a spider's capture web (1992) Proceedings of the Royal Society of London B, 248, pp. 143-148Evans, H.C., Natural control of arthropods, with special reference to ants (Formicidae) by fungi in the tropical high forest of Ghana (1974) Journal of Applied Ecology, 11, pp. 37-49Evans, H.C., Samson, R.A., Fungal pathogens of spiders (1987) Mycologist, 21, pp. 152-159Garcia, C.R.M., Japyassú, H.F., Estereotipia e plasticidade na seqüência predatória de Theridion evexum Keyserling 1884 (Araneae: Theridiidae) (2005) Biota Neotropica, 5 (1 A). , http://www.biotaneotropica.org.br/v5n1a/pt/, onlineGriswold, C.E., Coddington, J.A., Hormiga, G., Scharff, N., Phylogeny of the orb-web building spiders (Araneae, Orbiculariae: Deinopoidea, Araneoidea) (1998) Zoological Journal of the Linnean Society, 123, pp. 1-99Haupt, J., Fungal and rickettsial infections of some East Asian trapdoor spiders (2000) Proceedings of the 19th European Colloquium of Arachnology, pp. 45-49. , Toft S, Scharff N, editors. Århus: Aarhus University PressHiggins, L., Townley, M.A., Tillinghast, E.K., Rankin, M.A., Variation in the chemical composition of orb webs built by the spider Nephila clavipes (Araneae, Tetragnathidae) (2001) Journal of Arachnology, 29, pp. 82-94Levi, H.W., The spider genera Chrysso and Tidarren in America (Araneae: Theridiidae) (1957) Journal of the New York Entomological Society, 63, pp. 59-81Levi, H.W., More American spiders of the genus Chrysso (Araneae: Theridiidae) (1962) Psyche, 69, pp. 209-237Levi, H.W., The spider genus Helvibis (Araneae, Theridiidae) (1964) Transactions of the American Microscopical Society, 83, pp. 133-142Levi, H.W., Cosmopolitan and Pantropical species of theridiid spiders (Araneae: Theridiidae) (1967) Pacific Insects, 9, pp. 175-186Nentwig, W., The prey of web-building spiders compared with feeding experiments (Araneae: Araneidae, Linyphiidae, Pholcidae, Agelenidae) (1983) Oecologia, 56, pp. 132-139Nentwig, W., Prey analysis of four species of tropical orb-weaving spiders (Araneae: Araneidae) and a comparison with araneids of temperate zone (1985) Oecologia, 66, pp. 580-594Nentwig, W., Christenson, T.E., Natural history of the non-solitary sheetweaving spider Anelosimus jucundus (Araneae: Theridiidae) (1986) Zoological Journal of the Linnean Society, 87, pp. 27-35Platnick, N.I., (2005) The World Spider Catalog, Version 6.5 [Online], , http://research.amnh.org/entomology/spiders/catalog81-87/index.html, American Museum of Natural HistoryReiskind, J., Levi, H.W., Anatea, an ant-mimicking theridiid spider from New Caledonia (Araneae: Theridiidae) (1967) Psyche, 74, pp. 20-23Samson, R.A., Evans, H.C., New species of Gibellula on spiders (Araneida) from South America (1992) Mycologia, 84, pp. 300-314Stowe, M.K., Prey specialization in Araneidae (1986) Spiders, Webs, Behavior and Evolution, pp. 101-131. , Shear WA, editor. Palo Alto (CA): Stanford University PressStrongman, D.B., Gibellula pulchra from a spider (Salticidae) in Nova Scotia, Canada (1991) Mycologia, 83, pp. 816-817Tillinghast, E.K., Christenson, T., Observations on the chemical composition of the web of Nephila clavipes (Araneae, Araneidae) (1984) Journal of Arachnology, 12, pp. 69-74Tillinghast, E.K., Townley, M.A., Chemistry, physical properties, and synthesis of araneid orb webs (1987) Ecophysiology of Spiders, pp. 203-210. , Nentwig W, editor. Berlin: Springer VerlagTzean, S.S., Hsieh, L.S., Wu, W.J., The genus Gibellula on spiders from Taiwan (1997) Mycologia, 89, pp. 309-318Vollrath, F., Edmonds, D.T., Modulation of the mechanical properties of the spider silk by coating with water (1989) Nature, 340, pp. 305-307Vollrath, F., Fairbrother, W.J., Williams, R.J.P., Tillinghast, E.K., Bernstein, D.T., Gallagher, K.S., Townley, M.A., Compounds in the droplets of the orb spider's viscid spiral (1990) Nature, 345, pp. 526-528Whitehouse, M.E.A., The foraging behaviours of Argyrodes antipodiana (Theridiidae), a kleptoparasitic spider from New Zealand (1986) New Zealand Journal of Zoology, 13, pp. 151-168Whitehouse, M.E.A., The benefits of stealing from a predator: Foraging rates, predation risk, and intraspecific aggression in the kleptoparasitic spider Argyrodes antipodiana (1997) Behavioral Ecology, 6, pp. 663-667Whitehouse, M.E.A., Jackson, R.R., Predatory behaviour and parental care in Argyrodes flavipes, a social spider from Queensland (1998) Journal of Zoology, 244, pp. 95-10

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?

Spiders of the genus Cyclosa often add prey remains and other debris to their orb-webs. The function of silk decorations is generally associated with defense against predators or with the attraction of prey, but few studies have focused on stabilimenta containing detritus. In this study, we used artificial webs with and without the detritus stabilimenta of two species of Cyclosa to investigate whether these structures increase the number of insects intercepted. Artificial models of spiders and stabilimenta were used to compare the frequency of attacks against different shapes. We also conducted choice experiments in laboratory to determine whether detritus columns attracted Drosophila melanogaster (Diptera: Drosophilidae) and Trigona angustula (Hymenoptera: Apidae, Meliponinae) to the webs. The frequency of interception in artificial webs with a stabilimentum was similar to that of webs without such structure. The taxonomic composition and biomass of insects were also similar in both types of artificial webs. The choice experiments showed no significant tendency in attraction to webs with a stabilimentum. However, models of spiders were attacked at a higher frequency than those simulating detritus columns and silk decorations. These findings argue against the prey attraction hypothesis and suggest that the addition of stabilimenta to webs of Cyclosa could reduce the intensity of predation, possibly by disrupting the image of the spider's outline. © 2005 Blackwell Verlag.1115479491Alves-Costa, C.P., Lopes, A.V., Using artificial fruits to evaluate fruit selection by birds in the field (2001) Biotropica, 33, pp. 713-717Baba, Y., Testing for the effect of detritus stabilimenta on foraging success in Cyclosa octotuberculata (Araneae: Araneidae) (2003) Acta Arachnol., 52, pp. 1-3Bjorkman-Chiswell, B.T., Kulinski, M.M., Muscat, R.L., Nguyen, K.A., Norton, B.A., Symonds, M.R.E., Westhorpe, G.E., Elgar, M.A., Web-building spiders attract prey by storing decaying matter (2004) Naturwissenschaften, 91, pp. 245-248Blackledge, T.A., Stabilimentum variation and foraging success in Argiope aurantia and Argiope trifasciata (Araneae: Araneidae) (1998) J. Zool., 126, pp. 21-27. , LondBlackledge, T.A., Signal conflict in spider webs driven by predators and prey (1998) Proc. R. Soc. Lond. B Biol. Sci., 265, pp. 1991-1996Blackledge, T.A., Wenzel, J.W., Do stabilimenta in orb-webs attract prey or defend spiders (1999) Behav. Ecol., 10, pp. 372-376Blackledge, T.A., Wenzel, J.W., The evolution of cryptic spider silk: A behavioral test (2000) Behav. Ecol., 11, pp. 142-145Blackledge, T.A., Wenzel, J.W., Silk mediated defense by an orb web spider against predatory mud-dauber wasps (2001) Behaviour, 138, pp. 155-171Brodie III, E.D., Differential avoidance of coral snake banded patterns by free-ranging avian predators in Costa Rica (1993) Evolution, 47, pp. 227-235Brodie III, E.D., Janzen, F.J., Experimental studies of coral snake mimicry: Generalized avoidance of ringed snake patterns by free-ranging avian predators (1995) Funct. Ecol., 9, pp. 186-190Bruce, M.J., Herberstein, M.E., Elgar, M.A., Signalling conflict between prey and predator attraction (2001) J. Evol. Biol., 14, pp. 786-794Chaves, G.W., (1998) A Influência de Características Morfológicas e Comportamentais de Lagartas No Ataque de Predadores: Um Estudo Experimental Com Larvas Artificiais, , Master's Thesis, Univ. Estadual de Campinas, Campinas, BrazilCraig, C.L., Orb-web visibility: The influence of insect flight behaviour and visual physiology on the evolution of web designs within the Araneoidea (1986) Anim. Behav., 34, pp. 54-68Craig, C.L., Bernard, G.D., Insect attraction to ultraviolet-reflecting spider webs and web decorations (1990) Ecology, 71, pp. 616-623Craig, C.L., Wolf, S.G., Davis, J.L.D., Hauber, M.E., Maas, J.L., Signal polymorphism in the web-decorating spider Argiope argentata is correlated with reduced survivorship and the presence of stingless bees, its primary prey (2001) Evolution, 55, pp. 986-993Eberhard, W.G., Stabilimenta on the webs of Uloborus diversus (Araneae: Uloboridae) and other spiders (1973) J. Zool., 171, pp. 367-384. , LondEberhard, W.G., Substitution of silk stabilimenta for egg sacs by Allocyclosa bifurca (Araneae: Araneidae) suggests that silk stabilimenta function as camouflage devices (2003) Behaviour, 140, pp. 847-868Herberstein, M.E., Foraging behaviour in orb-web spiders (Araneidae): Do web decorations increase prey capture success in Argiope keyserlingi Karsch, 1878 (2000) Aust. J. Zool., 48, pp. 217-223Herberstein, M.E., Craig, C.L., Coddington, J.A., Elgar, M.A., The functional significance of silk decorations of orb-web spiders: A critical review of the empirical evidence (2000) Biol. Rev., 75, pp. 649-669Herberstein, M.E., Craig, C.L., Elgar, M.A., Foraging strategies and feeding regimes: Web and decoration investment in Argiope keyserlingi Karsch (Araneae: Araneidae) (2000) Evol. Ecol. Res., 2, pp. 69-80Hódar, J.A., The use of regression equations for estimation of arthropod biomass in ecological studies (1996) Acta Oecol., 17, pp. 421-433Madsen, T., Are juvenile grass snakes, Natrix natrix, aposematically coloured? (1987) Oikos, 48, pp. 265-267Pinto, I.A., (1997) Avaliação Experimental de Variações Espaciais e Temporais No Ataque de Larvas de Lepidoptera, , Master's Thesis, Univ. Estadual de Campinas, Campinas, BrazilRobinson, M.H., Robinson, B., The stabilimentum of the web spider, Argiope argentata: An improbable defence against predators (1970) Can. Entomol., 102, pp. 641-655Rovner, J.S., Detritus stabilimenta on the webs of Cyclosa turbinata (Araneae, Araneidae) (1976) J. Arachnol., 4, pp. 215-216Rypstra, A.L., Building a better insect trapan experimental investigation of prey capture in a variety of spider webs (1982) Oecologia, 52, pp. 31-36Scharff, N., Coddington, J.A., A phylogenetic analysis of the orb-weaving spider family Araneidae (Arachnida, Araneae) (1997) Zool. J. Linn. Soc., 120, pp. 355-424Schwartz, G., (2001) O Estudo de Interações Entre Larvas de Lepidópteros e Seus Predadores, Uma Abordagem Experimental Com O Uso de Modelos Plásticos, , Master's Thesis, Univ. Estadual de Campinas, Campinas, BrazilSeah, W.K., Li, D., Stabilimenta attract unwelcome predators to orb-webs (2001) Proc. R. Soc. Lond. B Biol. Sci., 268, pp. 1553-1558Sokal, R.R., Rohlf, F.J., (1995) Biometry, 3rd Edn., , W.H. Freeman & Co., New YorkTso, I.M., Stabilimentum of the garden spider Argiope trifasciataa possible prey attractant (1996) Anim. Behav., 52, pp. 183-191Tso, I.M., Isolated spider web stabilimentum attracts insects (1998) Behaviour, 135, pp. 311-319Tso, I.M., Stabilimentum-decorated webs spun by Cyclosa conica (Araneae: Araneidae) trapped more insects than undecorated webs (1998) J. Arachnol., 26, pp. 101-105Vasconcellos-Neto, J., Souza, A.L.T., Guimarães, M.M., Faria, D.M., Effects of color, shape and location on detection of cactus fruits by a lizard (2000) J. Herpetol., 34, pp. 306-309Watanabe, T., Prey attraction as a possible function of the silk decoration of the uloborid spider Octonoba sybotides (1999) Behav. Ecol., 10, pp. 607-611Zar, J.H., (1999) Biostatistical Analysis, 4th Edn., , Prentice Hall, Englewood Cliffs, NJZschokke, S., Ultraviolet reflectance of spiders and their webs (2002) J. Arachnol., 30, pp. 246-25

A New Species Of Baeus (hymenoptera: Scelionidae) From Brazil, Parasitoid Of Cyclosa Morretes (araneae: Araneidae)

Seven species of Baeus occur in the Neotropical and Andean regions: B. achaearaneus Loiácono, B. auraticeps Girault, B. kuscheli Ogloblin, B. latrodecti Dozier, B. metazygiae Loiácono et Margaría, B. platensis (Bréthes), and B. ventricosus Ogloblin. All of them are associated with spiders of the families Araneidae and Theridiidae. In this study, a new species of Baeus is described from egg sacs of Cyclosa morretes (Araneidae) collected in a natural reserve in São Paulo State, Brazil. The spider species is a new host for Baeus. We also evaluated the frequency of attacks and the impact of parasitism on the spider egg sacs.1172181187Austin, A.D., The fecundity, development and host relationships of Ceratobaeus spp. (Hymenoptera: Scelionidae), parasites of spider eggs (1984) Ecological Entomology, 9, pp. 125-138Austin, A.D., The function of spider egg sacs in relation to parasitoids and predators, with special reference to the Australian fauna (1985) Journal of Natural History, 19, pp. 359-376Austin, A.D., Johnson, N., Dowton, M., Systematics, evolution, and biology of Scelionid and Platygastrid wasps (2005) Annual Review of Entomology, 50, pp. 553-582Van, B.P., Sunderland, K.D., Topping, C.J., Eggsac parasitism of money spiders (Araneae, Linyphiidae) in cereals, with a simple method for estimating percentage parasitism of Erigone spp. eggsacs by Hymenoptera (1994) Journal of Applied Entomology, 118, pp. 217-223Brèthes, J., Himenópteros de la America Meridional (1913) Anales del Museo Nacional de Buenos Aires, 24, pp. 35-165Dozier, H.L., A new scelionid egg parasite of the black widow spider (1931) Proceedings of the Entomological Society of Washington, 33, pp. 27-28Girault, A.A., Notes on two South American parasitic Hymenoptera (1915) The Entomologist, 48, pp. 213-214Gillespie, R.G., Costs and benefits of brood care in the hawaiian happy face spider Theridion grallator (Araneae, Theridiidae) (1990) American Midland Naturalist, 123, pp. 236-243Gonzaga, M.O., (2004) Funções e Variabilidade Estrutural Dos Estabilimentos Construídos Por Cyclosa Fililineata Hingston 1932 e Cyclosa Morretes Levi 1999 (Araneae: Araneidae), , Ph.D. thesis, Universidade Estadual de Campinas, SP, BrazilGonzaga, 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. 479-491Johnson, N., (2004) Scelionidae, , http://atbi.biosci.ohio-state.edu:210/hymenoptera/eol_scelionidaeLevi, H.W., The Neotropical and Mexican orb weavers of the genera Cyclosa and Allocyclosa (Araneae: Araneidae) (1999) Bulletin of the Museum of Comparative Zoology, 155, pp. 299-379Loiácono, M.S., Notas sobre Proctotrupoideos Neotropicales I (Hymenoptera) (1973) Neotrópica, 19, pp. 138-140Loiácono, M.S., Margaría, C.B., Las especies del género Baeus (Hymenoptera: Scelionidae) endoparasitoides de ootecas de arañas en la región neotropical (2004) Acta Zoológica Mexicana, 20, pp. 83-90Masner, L., Denis, J., The Nearctic species of Idris Foerster. Part I: The melleus-group (Hymenoptera: Scelionidae) (1996) Canadian Entomology, 128, pp. 85-114Morrone, J.J., Biogeografía de América Latina y el Caribe (2001) M&T-Manuales & Tesis SEA, , CYTED, ORCyT-UNESCO & SEA (Eds.), 148 ppOgloblin, A., Los insectos de las Islas Juan Fernández (1957) Revista Chilena Entomología, 5, pp. 413-444Valerio, C.E., A unique case of mutualism (1974) American Naturalist, 109, pp. 235-238Valerio, C.E., Two alternative strategies for spider egg parasitoids (1984) Revista de Biología Tropical, 32, pp. 123-128Vetter, R.S., Bruyea, G.P., Visscher, P.K., The use of bleach to dissolve spider silk (1996) Bulletin of British Arachnological Society, 10, pp. 146-14

Orb-web Spiders (araneae: Araneomorphae; Orbiculariae) Captured By Hunting-wasps (hymenoptera: Sphecidae) In An Area Of Atlantic Forest In South-eastern Brazil

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? 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Female sexual maturity as a determining factor of size-assortative pairing in the protandrous spider Manogea porracea (Araneae, Araneidae)

Protandry occurs when males mature prior to females in the breeding season. There may be a fitness benefit for males if they are able to copulate and defend virgin and more fecund females. Therefore, fitness benefits can be investigated by studying assortative mating during mate guarding of virgin females before and after female sexual maturation. The asynchrony of female development in the protandrous spider Manogea porracea (Araneidae) provides an opportunity to investigate how female sexual maturity (subadult and adult females) influence size-assortative pairing. We investigated size differences between couples composed of males and subadult females, and of males and adult females. We hypothesized that size-assortative pairing is stronger in couples with adult females. Adult females were larger than subadults, but the size of males paired with females from both groups was similar. We found assortative pairing within all couples involving an adult female. However, this pattern was not observed among couples with subadult females. It is possible that the production of sexual pheromones by adult females after their last molt intensifies male intrasexual competition, promoting positive assortative pairing. We discuss the potential mechanisms affecting male mate choice and mate competition during pairings in M. porracea28416CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MINAS GERAIS - FAPEMIGFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP306157/2014-4; 403733/2012-0; 445832/2014-2; 465562/2014-0; 441225/2016-0sem informaçãoAPQ-02984-17; APQ-02104-14; CRA-30058/12; APQ-03202-13; APQ-02474-15465562/2014-0; 2017/14196-5We thank Giancarlo MSc. Ângelo Ferreira and Yuri Lima Vasconcelos Ferreira for providing transport to the study area in several occasions. We also thank Dr. Gustavo Requena for his important contributions to the first drafts. This project was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (São Paulo Research Foundation, FAPESP: Proc. 465562/2014-0; 2017/14196-5), Duratex S.A., Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Instituto Nacional de Ciência e Tecnologia dos Hymenoptera Parasitoides da Região Sudeste (HYMPAR/Sudeste – CNPq/CAPES/FAPESP), Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG: Proc. APQ-02984-17, APQ-02104-14, CRA-30058/12, APQ-03202-13; APQ-02474-15), and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq: Proc. 306157/2014-4; 403733/2012-0; 445832/2014-2; 465562/2014-0; 441225/2016-0

Prey Capture Behaviour In The Social Spider Anelosimus Eximius (araneae: Theridiidae): Responses To Prey Size And Type

Some species of web building spiders use different capture tactics for different prey types. The main factors influencing the attack behaviour are the ability of the insect to escape, the risks of injury to the spiders and prey size. This study evaluated the effects of size and prey type on prey capture behaviour of the social spider Anelosimus eximius as influenced by the number of spiders attracted by prey movements that did not bite until the immobilization (bystanders) and the number of spiders that contributed to prey immobilization (catchers). We carried out a two-factor (prey size and type) experiment offering prey belonging to four orders: Diptera, Lepidoptera, Hymenoptera and Orthoptera, in a size gradient within each prey type. Both factors influenced the number of spiders recruited as bystanders, but only prey body size influenced the number of catchers in the subduing process. The possible advantages of the presence of bystanders around the interception site are discussed. © 2007 The Authors.1139856861Amir, N., Whitehouse, M.E.A., Lubin, Y., Food consumption rates and competition in a communally feeding social spider, Stegodyphus dumicola (Eresidae) (2000) J. Arachnol., 28, pp. 195-200Avilés, L., Causes and consequences of cooperation and permanent-sociality in spiders (1997) The Evolution of Social Behavior in Insects and Arachnids, pp. 476-499. , In: Choe, J. Crespi, B., eds). Cambridge Univ. Press, Cambridge, ppBarnard, C.J., Sibly, R.M., Producers and scroungers: A general model and its application to captive flocks of house sparrows (1981) Anim. Behav., 29, pp. 543-555Box, G.E.P., Hunter, W.G., Hunter, J.S., (1978) Statistics for Experimenters: An Introduction to Design, Data Analysis and Model Building., , Wiley, New YorkCaraco, T., Risk sensitivity and foraging groups (1981) Ecology, 62, pp. 527-531Caraco, T., Uetz, G.W., Gillespie, R.G., Giraldeau, L., Resource consumption variance within and among individuals: On coloniality in spiders (1995) Ecology, 76, pp. 196-205Clark, C.W., Mangel, M., The evolutionary advantages of group foraging (1984) Theor. Popul. Ecol., 30, pp. 45-75Ebert, D., Behavioral asymmetry in relation to body weight and hunger in the tropical social spider Anelosimus eximius (Araneae, Theridiidae) (1998) J. Arachnol., 26, pp. 70-80Gonzaga, M.O., Vasconcellos-Neto, J., Collective prey capture and feeding behaviours of Anelosimus jabaquara Levi 1956 (Araneae: Theridiidae) (2002) Behaviour, 139, pp. 573-584McMahon, T.A., Bonner, J.T., (1986) Tamaño Y Vida., , Prensa Cientifica, BarcelonaNentwig, W., Social spiders catch larger prey: A study of Anelosimus eximius (1985) Behav. Ecol. Sociobiol., 17, pp. 79-85Pasquet, A., Krafft, B., Cooperation and prey capture in a social spider Anelosimus eximius (Araneae, Theridiidae) (1992) Ethology, 90, pp. 121-133Pulliam, H.R., Caraco, T., Living in groups: Is there an optimal group size? (1984) Behavioural Ecology: An Evolutionary Approach, pp. 122-147. , In: 2nd edn (. Krebs, J. R. Davies, N. B., eds). Sinauer Associates Inc Publishers, Sunderland, MA, ppRanta, E., Peuhkuri, N., Laurila, A., Rita, H., Metcalfe, N.B., Producers, scroungers and foraging group structure (1996) Anim. Behav., 51, pp. 171-175Rita, H., Ranta, E., Peuhkuri, N., Group foraging, patch exploitation time and the finder's advantage (1997) Behav. Ecol. Sociobiol., 40, pp. 35-39Rypstra, A.L., Foraging success of solitary and aggregated spiders: Insights into flock formation (1989) Anim. Behav., 37, pp. 274-281Rypstra, A.L., Prey capture and feeding efficiency of social and solitary spiders: A comparison (1990) Acta Zool. Fenn., 190, pp. 339-343Rypstra, A.L., Prey size, social competition, and the development of reproductive division of labor in social spider groups (1993) Am. Nat., 142, pp. 868-880Rypstra, A.L., Tirey, R.S., Prey size, prey perishability and group foraging in a social spider (1991) Oecologia, 86, pp. 25-30Snedecor, G.W., Cochran, W.G., (1989) Statistical Methods, , 8th edn. Iowa State Univ. Press, Ames, IAUetz, G.W., The ''ricochet effect'' and prey capture in colonial spiders (1989) Oecologia, 81, pp. 154-159Vollrath, F., Rohde-Arndt, D., Prey capture and feeding in the social spider Anelosimus eximius (1983) Z. Tierpsychol., 61, pp. 334-340Ward, P.I., Enders, M.M., Conflict and cooperation in the group feeding of the social spider Stegodyphus mimosarum (1985) Behaviour, 94, pp. 167-182Whitehouse, M.E.A., Lubin, Y., Competitive foraging in the social spider Stegodyphus dumicola (1999) Anim. Behav., 58, pp. 677-688Willey, M.B., Jackson, R.R., Predatory of a social spider Stegodyphus sarasinorum (Araneae: Eresidae): why attack first? (1993) Can. J. Zool., 71, pp. 2220-222