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 […]

Eurithia – female sternite 6

These are some figures from Tschorsnig & Herting (1994), showing the sternite 6 of some female Eurithia spp.:

A – Eurithia consobrina (furrow along entire length)

B – Eurithia connivens (furrow on only anterior half)

C – Eurithia vivida & intermedia (anterior indentation)

Unfigured (sternite domed) – Eurithia caesia & anthophila (slightly)

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Some name changes

Belshaw’s 1993 handbook was a great improvement over the nomenclature used in van Emden but since then many of the names have changed. This is pretty boring stuff, so I apologise in advance, but here are the changes and explanations, as far as I know them:

Timavia Robineau-Desvoidy 1863 is a junior synonym of Smidtia […]

Panzeria, Eurithia, Appendicia & Fausta male genitalia

This is a reprint of the genitalia figures from van Emden’s 1957 handbook – out of print for many years. I find them quite useful for double-checking males – if I get good feedback then I might turn this into a larger article.

For reference the key to this diagram is:

P – Panzeria […]

A typical tachinid wing

This is a photograph of a Tachina grossa wing, annotated to show the commonest features that are used in the keys:

I always orient myself by looking for the smallest vertical vein called r-m, the little one in the middle – it links the last true radial vein (r4+5) to the median. The median vein […]