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| Insects of Britain and Ireland: the families of Diptera |
Dorilaidae, Dorylaidae
Big-headed Flies.
Life style parasitic; on Homoptera.
Adult insects. Antennae 3 segmented (the third segment variable in form); ‘modified’; with a non-annulated terminal segment; aristate; the arista dorsal (usually long). Ptilinal suture absent or weakly defined. Eyes asymmetric, nearly or quite connected above the antennae (usually, in males), or rounded, well separated (usually narrowly separated in females). Mouthparts very small. The maxillary palps 1 segmented; porrect. Wings with a discal cell (large); with a subapical cell; with a closed anal cell. The anal cell relatively long. Sub-costa apparent; reaching the costa independently of vein 1. The leading edge veins markedly stronger than the rest, or not noticeably stronger than the rest. Wing vein 3 not forked. Feet without a triple pad.
Larvae and pupae. The larvae terrestrial; parasitic; endoparasitic (of Homoptera); acephalic. The pupae enclosed within a puparium.
Comments. Hovering insects, with a very large head consisting almost entirely of the compound eyes. Females with a recurved, pointed ovipositor.
Classification. Suborder Brachycera; Division Muscomorpha Aschiza; Superfamily Syrphoidea.
British representation. 92 species in Britain. Genera 11; Cephalops, Cephalosphaera, Chalarus, Dorylomorpha, Eudorylas, Jassidophaga, Microcephalops, Nephrocerus, Pipunculus, Tomosvaryella, Verrallia.
Illustrations. • 'Pipunculus pratorum', cf. P. thomsoni: B. Ent. 757. • 'Pipunculus pratorum', cf. P. thomsoni: B. Ent. 757, legend+text. • 'Pipunculus pratorum', cf. P. thomsoni: B. Ent. 757, text cont.. • Chalarus and Pipunculus (from Walker). 6a-f, Pipunculus campestris. 6a, head of male; 6b, head of female; 6c, antenna; 6d, proboscis, from the side; 6e, wing; 6f, extremity of male abdomen. 6g, Verrallia aucta, wing. 7, Chalarus spurius. 7a, face of female; 7b, antenna; 7c, middle leg; 7d, extremity of tarsus. From Walker (1851, Plate VIII), with 2mm scale added.
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. Insects of Britain and Ireland: the families of Diptera. Version: 14th April 2022. delta-intkey.com’.
