Looks fine for a male inflata

Sphegina is a genus that looks like it's intermediate between Baccha and Neoascia. But separation of the species is not easy.

Does anyone have a list of literature for aquatic larvae to obtain for identification?

Many thanks Howard, that looks very promising, and will be my first encounter with the Milichiidae! I'll key it out properly when I get a chance, but Madiza pachymera also looks like a possibility, judging by Nigel Jones's photo here (which was also from a flight interception trap):

https://diptera.info/photogallery.php?photo_id=10342

Ken Smith's (yellow) book has a comprehensive list of references (albeit concentrating on the British Fauna). 

The other book you should try to get is Aquatic Insects of North Europe, volume 2 - which is mostly Diptera. (editor Anders Nilsson). Again it has extensive lists of references at the end of each family chapter. 

This does indeed key out as Madiza pachymera - thanks again Howard for putting me on the right track.

Oh! Just taken another look and it may be an Anthomyiidae - the anal vein reaches the wing edge. It doesn't have the usual small bristle on its hind metatarsus though, or at least it is not evident.

I'd agree with Anthomyiidae - the combination of pale hairs under the scutellum and the anal vein reaching wing margin is pretty diagnostic.

Hi, I've been trying to find out about the status of this key, but with no luck so far. If I can get further information I'll let you know.

There is a key by Stuart Ball available on the old Dipterists' Forum website at http://www.dipteristsforum.org.uk/documents/Family%20Sciomyzidae%20v2.pdf . You may need to sign on as a member of the Dipterists Forum to access this. 

Thank you very much, Tony.

I am a new member ;-)

Thanks Martin.

Looks to me like Phaonia turguriorum female

Tony, does seem to fit with keys and features, many thanks for ID.  John

I'd say not lancifer, which has much darker legs. Either Hydrophoria or Hylemya. In Hydrophoria, the lower squama exceeds the upper in length, in Hylemya, it is the same or narrower. I can't quite judge which from your photos, but you should be able to tell. I am assuming you have a copy of Mike Ackland's keys to Anthomyiidae - this is not a family to identify from on-line images!

Sorry you've had trouble with this. We're not aware of a problem with the website, so if you follow the steps given on the Help page under "Recommended method for adding images" it should work. Once the file has uploaded you need to scroll down and click the "Save" button. Could you try again and let me know exactly how far you get, and if possible take a screenshot if something goes wrong?

I hope you been able to access Stuart's key via the link the Tony provided, but if not the same key is now available from our members' page.

Yes, I did access the key via Tony's link. Now I also have the other resources - just what I needed. Thank you!

I agree with Martin's identification. The only other British contender is rufibarbis whose face is the same brown or slightly golden colour all over, but albiceps has a few short but obvious setae on the mid and hind femora (almost absent in rufibarbis). You cannot see another good character, which is the rather undistinguished ventral hairs on all the femora in this species, but which in rufibarbis are clearly longer (up to half the femora depth) and more upright and often pale. And, as Fonseca says, the front coxa hairs are black, at least on the outer face (not 'entirely' as he incorrectly says), compared to all yellow and much longer in rufibarbis.

All my albiceps (and rufibarbis) females have rich dark brown dusted frons, not a hint of silver.

H.albiceps is mainly found in Scotland (but we have it on Dartmoor) so Islay is spot on.

Thanks Martin, a new species for me, and one that was great fun to watch skimming over the dark peaty water in the company of whirligig beetles and pond skaters.