Identifying the bronze-black Spring tachinids

Work in progress…

Spring can be an exciting time for Dipterists, when the first species emerge and we all clamour to identify our first flies. However, a few of the species can be quite tricky to identify from photos because they look superficially quite similar. That said, it can be possible to identify most of them if you can see a few of the key features and compare them against some pre-identified photos.

I haven’t provided a key to these species but you should be able to see the features in the following photos and descriptions:

  • Ramonda spathulata: bare eyes, strong bristles along the length of the parafacial, steeply curved post-bend median vein, extra pair of ocellar bristles. Receding “chin” giving a forward-leaning face.
  • Lypha dubia: densely hairy eyes, face slightly sloped – contrast with Ramonda which has a “normal” head shape; post-bend median vein less concave. If you can see under the wing the pteropleural bristle would be long – reaching back to the calypters and the hind spiracle would be open with a pair of equally-sized flaps.
  • Macquartia sp.: Hairy eyes, quite close together – 3 pairs of scutellar bristles. Females of some species are brown with orange legs. All have hairy eyes and a very sloping face profile, with 3 pairs of scutellar bristles.
  • Brachychaeta strigata: relatively large head on a very anonymous black & grey fly. The most noticeable feature is that the frons is much wider than an eye, when viewed from above. Some of the body bristles seem exceptionally long – standing much higher than the depth of the abdomen or extending a long way from the scutellum. Media vein is not sharply angled or concave.
  • Triarthria setipennis: a small grey fly with very long basal arista segments. The arista on other tachinids is straight and quite thin so is often difficult to make out but on Triarthria it can often be easy to see the angled segments. Only Gonia and Germaria in Britain share this feature and they are very different looking flies.