Tachinid Flies
What are they?
Tachinids may be considered rather gruesome by some people, for their larvae live as internal parasitoids of other insects. Females lay eggs either on foliage - to enter a host when eaten with foliage - or eggs are layed directly onto or into the host species. Some larvae are maggot-like but others are flattened creatures called planidia, which may actively seek out their host. These are very common insects, with the adults often seen feeding at flowers throughout the summer months.
Identification
This is a large and very diverse group, with most species either being stout and resembling typical flies, or being narrow-waised and wasp-like. Many tachinid flies can be recognized as such by the scattering of rather stout, bristly hairs on the abdomen. Identification to species can be difficult for some of the rather nondescript species, but some species have distinctive abdomen colors and markings, while details of leg color and wing coloring (if present) can be useful too.
Archytas sp.
A drab fly with an orange wash to the base of the wings. Larvae known to be parasitoids of moth caterpillars.
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Cylindromyia sp.
A genus of relatively slender tachinids which may be all black or have reddish patches on the abdomen. Resembling wasps, these flies are often found feeding on Wild Carrot flowers. Larvae known to be parasitoids of moth caterpillars and some species of true bugs.
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Gymnosoma fuliginosa
Adults regularly seen feeding at flowers in summer, especially the flowers of Wild Carrot. Larvae feed on pentatomid bugs.
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Trichopoda pennipes
A fairly common member of the feather-legged fly group, this species can often be found on the flowers of members of the carrot family. Note the peculiar comb-like hairs on the back legs.
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