Gymnocheta magna found in Scotland
Exciting news this week from Steve Falk who, while examining specimens caught in Scotland this year, noticed a different-looking Gymnocheta from the Cairngorms. He ran it through the key by Pohjoismäki & Bergström (2021) and it came out clearly to Gymnocheta magna, a new species for the UK!
G.magna has been found fairly frequently across northern Europe (in particular Scandinavia) and so a record for Scotland is a welcome surprise but is reasonable to expect. The paper added 2 more Scandinavian Gymnocheta spp. (lucida & zhelochovtsevi) so it is possible that they have just been overlooked because people assumed that they knew the identify of bristly, green flies in Spring and didn’t take the time to look at them carefully.
Splitting the 2 UK species should be fairly simple (see below) and might be helped in that we’d expect G.magna to only occur in northern latitudes, but this shouldn’t prevent everyone checking their specimens, no matter there they caught them.
Differences
Here I am using Steve’s Excellent photos from his Flickr site, which you can see in higher resolution here: Gymnocheta magna (Large Green Parasite Fly) | Flickr
| Features | Gymnocheta viridis | Gymnocheta magna |
|---|---|---|
| The face of magna is more “scooped out” with a more projecting mouth edge than viridis. This feature is probably going to be difficult to judge and will vary between sexes. |  |  |
| Costal spine is present in viridis but absent in magna. This feature seems the easiest and clearest to use. |  |  |
| Leg colour is brighter in magna than in viridis. I would expect this to be hard to judge in some specimens. |  |  |
References
- Pohjoismäki & Bergström (2021) Review of the Nordic Gymnocheta Robineau-Desvoidy (Diptera, Tachinidae) with report of two species new to Europe.
