Tachinidae - Parasite-flies

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Classification

BRACHYCERA, Muscomorpha Schizophora Calyptratae, Oestroidea

Number of British species: 254

Size: S-L

Difficulty: 2-4

Scheme: Covered by the Tachinid recording scheme

See also the Tachinid recording scheme web-site

Characters

Small to large (2-20 mm) flies. Most species are grey to slate black, in some cases with yellow or red spots on the sides of abdomen; some species are metallic green or yellowish grey. Usually many bristles are present, some species may, however, be quite bare or show a bee-like pilosity. Arista usually quite bare, rarely plumose. Wing with vein M1 usually strongly curved forward, sometimes cell r4+5 is petiolate. Lower calypter usually broadly rounded-triangular, in some cases small and elliptical. Meral bristles always present; subscutellum strongly developed (except in Litophasia); lappets of posterior spiracle usually distinctly unequal in size, the posterior lappet subcircular, in several genera about equal in size.

Biology

The larvae are endoparasitoids of other insects, sometimes of other arthropods. Eggs are deposited directly on or in the immediate vicinity of the host. The larvae of tachinids which deposit their eggs directly on the host hatch within minutes (ovolarvipary) and penetrate the host. A conspicuous specialisation is the development of microtype eggs by species of the tribe Goniini in the subfamily Exoristinae. Here, tens of thousands of eggs are deposited on leaves. The eggs only develop after a caterpillar has eaten them (along with the leaves they feed on), after which they hatch inside the caterpillar's digestive tract. Hence, most Goniini show a wide range of lepidopterous hosts. Some other groups show host specialisation: the Dexiini are parasitoids of beetles, the Exoristinae and Tachininae are mainly parasitoids of caterpillars and the larvae of the Phasiinae develop inside true bugs (Hemiptera); others parasitise besides caterpillars also larvae of Tipulidae (Tachininae: Siphona). Several species are of economic importance, being useful in biological pest control. The adults of the Tachinidae are largely found on walls, leaves, branches and similar spots; only a small number of species regularly visit flowers. Some species are territorial.

Identification

 
families/brachycera/calyptrates/tachinidae.txt · Last modified: 2008/05/24 17:01 (external edit)     Back to top
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