Acrocerid (Insecta: Diptera) Life Histories, Behaviors, Host Spiders (Arachnida: Araneida), and Distribution Records

Abstract

The Canadian Entomologist 125: 931-944 (1993) The family Acroceridae (Tnsecta: Diptera; "Small Headed Flies") are a seldom seen yet cosmopolitan group of endopansitoids of spiders. Recent host and distribution records are presented here for six species of acrocerids: Ogcodes bnreulis Cole. 1919; Ogcoir'es pu/lidipennis (Loew. 1866); Ogcodes sp. ; Acroceru bimucularu Loew. l8*, Turbopsebiur srtlphuripes (loew, 1869); and Exetasis eickstedtae Schlinger, 1972. New hosts for each fly species are: 0. borealis-Schizocosa rovncri Uetz and Dondale, 1979, Pardusa spp. ; 0. pul/idipenni.~4chizocosu rovneri, Schizocnsu spp.; Ogcodes sp.-Anyphaena californica (Banks, 1904); Acrocera bimaculata--Coras montanus (Emerton, 1890b); T. sulphuripes-4. montanus.Detailed field measurements and behavioral observations of host spiders and fly development are described and compared with known data. Examination of these comparisons suggests that host-parasitoid relationships follow spider guild aqsociations (i.e. groundlsurface dwelling hosts or those building webs in close contact with surfaces), especially with the spider family Agelenidae. These affiliations probably result from a combination of the spider's web building. web maintenance, hunting hehaviors. and fly oviposition activities, which dispose spiders exhibiting these hehaviors to greater chances for parasitoidism. These factors act in concen to increase probabilities for host-parasitoid interactions. Compiled data indicate duration of pupation may be related to ambient temperature. Evidence is presented that acrocerid larvae may alter their hosts' behavior to increase the parasitoids' probability of survival. Cady, A., R. Leech, L. Sorkin, G. Stratton et M. Caldwell. 1993. Les Acroceridae (Insecta: Diptera): cycles biologiques, comportements, araignkes hBtes et rkpartitions gkographiques. The Canadian Entomologist 125: 931-944. Resume La famille des Acroceridae (Insecta: Diptera; "mouches a petite tEte") constitue un groupe d'insectes rarement vus et pourtant cosmopolites, parasites d'araignkes. On trouvera ici une liste de donnCes rkcentes sur les hBtes et les rCpartitions de six espkces d'acrockres: Ogcodes borealis Cole, 1919, Ogcodes pallidipennis (Loew, 1866), Ogcodes sp., Acrocera bimaculata Loew, 1866, Turbopsebius sulphuripes (Loew, 1869) et Exetasis eickstedtae Schlinger, 1972. Pour chacune de ces esp&ces, les nouveaux hBtes rencontrks sont: dans le cas d'O. borealis, Schizocosa rovneri Uetz et Dondale, 1979 et Pardosa spp., dans le cas d'O. pallidipennis. Schizocosa rovneri et Schizocosa spp., dans le cas d'ogcodes sp., Anyphaena californica (Banks, 1904), dans le cas d'Acrocera bimaculata, Coras montanus (Emerton, 1890b) et dans le cas de T. sulphuripes, C . montanus.Des mesures detaillees et des observations du comportement des araignees h8tes recueillies sur le terrain sont presentees ici et comparees aux donnees de la litterature. Les comparaisons indiquent que les relations h8tes-parasito'ides se font en fonction des guildes d'araignees (i-e. hBtes habitan...

Megaselia scalaris(Diptera: Phoridae): an opportunistic endoparasitoid of the endangered Mexican redrump tarantula,Brachypelma vagans(Araneae: Theraphosidae)

“…Dermestid larvae (Coleoptera) parasitize captive Brachypelma smithi (Pickard-Cambridge 1897) specimens (Paré et al 2001). Species of two Diptera families, Phoridae (Weinman & Disney 1997) and Acroceridae (von Eickstedt 1971(von Eickstedt , 1974Cady et al 1993), have also been reported as tarantula parasitoids.…”

Proximate mechanism of behavioral manipulation of an orb-weaver spider host by a parasitoid wasp

“…Interestingly, it is also possible that the manipulation of spiders by another taxonomical group, Diptera larvae of Acroceridae, involves the same hormone. These endoparasites of spiders also induce behavioral changes in web building behaviors that result in web designs similar to those of molting webs [35,36]. …”

New spider flies from the Neotropical Region (Diptera, Acroceridae) with a key to New World genera

“…Some species feed at flowers, and may be specialized pollinators, as suggested by their long proboscises (often equal to their body length), nectar feeding habits and pollen loads (Borkent and Schlinger 2008a, b). All species with known immature habits are parasitoids of spiders (Schlinger 1981, 1987; Cady et al 1993; Larrivée and Borkent 2009). …”