Tachinids that look like Eriothrix rufomaculata

Eriothrix rufomaculata is an incredibly common fly in mid-summer, especially on any flowery meadows. The species is very easy to identify from the red abdominal side-patches, silvery face with projecting mouth edge, long costal spine, slightly shaded wings with a small petiole on the median vein. The only problem is that several other, rarer, […]

A quick guide to the new UK phasiines

This year we have been lucky enough to receive records for 2 new species to the UK – Ectophasia crassipennis & Phasia aurigera. These both bear a resemblance to Phasia hemiptera and have been confused with them in the past so I thought I’d put together a few pointers on how to spot them.

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How to split Tachina fera type tachinids in photos

One of the most difficult problems is how to confirm/verify the identification of photos of flies that look quite like Tachina fera. I’d include in that group any of the following species: Tachina fera, Tachina magnicornis, Nowickia ferox, Linnaemya vulpina, Peleteria rubescens, Peleteria iavana & male Nemoraea pellucida. They’re all fairly large, bristly flies […]

Dexiosoma caninum vs Dexia vacua

I always find that one of the hardest identifications to make from photos is the split between Dexiosoma caninum and the much rarer Dexia vacua. Dexia vacua is so rare that many experts thought that it was extinct in Western Europe so getting good, reliable records from photos is very important because it seems […]

The problem with Phryxe …

The genus Phryxe contains a few common species (nemea, vulgaris & heraclei) and a few very rare ones (magnicornis & erythrostoma). The key pulls out nemea first by the wide gap between the facial-ridge bristles and the descending parafrontals – wider than the width of antenna-3 plus the mustardy/yellow frontal area. Splitting off heraclei has […]

Gonia face colour

In the keys to Gonia one of the couplets asks you to consider the shininess of the face but this can be a confusing thing to judge when you only have one specimen. In this mini article I have taken photos of the 2 choices to make it clear. The first thing to do is […]

Linnaemya picta, tessellans & rossica confusion features

For many years Linnaemya picta had been confused with rossica because early workers (e.g. Fonseca) hadn’t tried using the European keys. Since the ‘discovery’ of picta in Kent it has spread across southern England as far as Bedfordshire, Oxfordshire & Berkshire and so now we have another fairly common black-legged species to confuse with tessellans. […]

Exorista rustica vs. tubulosa

I always find this species-pair really difficult to split – even when you flip out the male genitalia. The cerci are actually quite distinctive but without good photos you can try to convince yourself that a rustica (the common one) is a tubulosa (the uncommon one). The key is that tubulosa should be really very […]

How to find the prosternum

The prosternum can be quite a difficult feature to find on a tachinid – partly because many British workers, used to Belshaw’s key will never have had to find it unless they have used the European or Palearctic keys. Here is a nice photo and the prosternum is the thin, dark, vertical strip of chitin […]

Distinguishing species of Thelaira

In my experience a lot of people have trouble with this genus because the traditional features used in keys are quite variable. In particular it is difficult to separate the common Thelaira nigripes from the rare solivaga.

All keys use the size of the outer-vertical bristles and the anterodorsal bristles on the middle tibia, which […]