Is this Chrysotoxum cautum or elegans

[Geoff F]

I had thought that this old thread would be well past it's 'sell by date' now, but it has suddenly sprung into a round of new life. And extremely interesting it is.

Charlieb, that Devon Wildlife Recording Centre is where I had started sending my records. Usually they replied to ask for the photos for double checking my suggested ID's. Then they started requiring expert ID before submission and, so far, I haven't sent in anything else; but I haven't really seen much of interest lately anyway.

Roger, I am currently checking through my images of the past 2 years so I will put together my confirmed sightings with definite locations and send it on to you. While there is little of any real excitement here, hopefully it might fill in a few missing holes in the location squares.

[ChrisR]

Originally Posted by JRsbugs

I'm not sure what the best line of approach here is. I had thought of privately mailing Andre to ask what his ID criteria was, he may have had an off day but then again not.

Well, I doubt he would be upset if you just asked for clarification - you want to learn the differences yourself and any expert should be able to justify their IDs

One point about taking IDs from pics, I must say that in a good number of cases a fly would not have been caught, or in my case I don't want to catch them. This surely gives rise to many valid records which otherwise would have been missed. With the improvement of digital camers, combined with an individual's passion and desire to take photos, this has to be a bonus to any recording scheme.

Well, I have to be careful here because I enjoy giving out identifications for photos (if I can) and there are obviously species that are so distinctive and so unlikely to be anything else (e.g. Tachina grossa, Mintho rufiventris, Eriothrix rufomaculata etc.) that the record would probably be accepted.

But, for instance, if you post a normal photo of a Phryxe sp. with parafrontal bristles almost meeting the facial-ridge bristles then I'd have to say that it looks like Phryxe vulgaris ... but I can't disprove P.heraclei because I can't see the bristlets on the underside of the costal vein and I can't discount P.magnicornis because I can't see the male genitalia - so I wouldn't accept it as a record. Same goes for the Phania funesta example - I am going to be right 99% of the time but I can't discount P.thoracica because I can't count the tibial spurs on the hind legs, so I wouldn't take the record again

[Roger Morris]

Yes you are so right Jason - just the right approach. All records are useful. It does strike me that there may be a benefit from developing a theme on this issue - would you be prepared to start one - I am a bit of a luddite and as yet don't know how!

By the way, I've just spent two days going through all of the photos on Wild About Britain and have extracted usable data from 143 entries that we had not found elsewhere. Nothing terribly impressive but all useful. This sort of return for effort is fairly good bearing in mind the time of year - I would not be out recording! However, there were many more (probably the same again) with no data. Just by way of information here is the breakdown of records.

40 species were recorded. For most there were just single or a couple of records. The breakdown is at the end of this message. One of the most noticeable points I think is that most contributors are from southern England or the Midlands. Very few from Scotland or northern England. This seems to miror data coming in from other sources but I'm at a loss to know why - surely there are lots of field naturalists in Scotland?





Anasimyia contracta, 2; Baccha elongata, 1; Chrysotoxum bicinctum, 1; Chrysotoxum cautum, 1; Chrysotoxum elegans, 1; Chrysotoxum festivum, 2; Dasysyrphus tricinctus, 1; Dasysyrphus venustus, 2; Epistrophe grossulariae, 1; Episyrphus balteatus, 15; Eristalinus sepulchralis, 1; Eristalis arbustorum, 3; Eristalis interruptus, 2; Eristalis intricarius, 2; Eristalis pertinax, 9; Eristalis tenax, 9; Eupeodes corollae, 2; Helophilus pendulus, 18; Helophilus trivittatus, 2; Leucozona lucorum, 2; Melanostoma scalare, 3; Meliscaeva cinctella, 2; Merodon equestris, 3; Myathropa florea, 4; Platycheirus albimanus, 1; Rhingia campestris, 8; Rnhingia rostrata, 1; Scaeva pyrastri, 1; Scaeva selenitica, 1; Sericomyia silentis, 4; Sphaerophoria scripta, 2; Syritta pipiens, 1; Syrphus ribesii, 3; Tripidia scita, 1; Volucella bombylans, 8; Volucella inanis, 2; Volucella pellucens, 6; Volucella zonaria, 7; Xanthogramma pedissequum, 4; Xylota segnis, 4.

[JRsbugs]

Great going Roger.

I have started a thread for Syrphid ID and records.

RECORDS Syrphid (Hover) flies for ID

[JRsbugs]

I brought the fly in question thread up and have had a rely from someone else. This is the difference between the two, one point I did noticed when looking again was the yellow at the edge of tergite 5.

In E. lapponicus, the side margin of tergite 5 is at least partly black, while in this specimen it is entirely yellow. E. luniger is much more likely, based on the yellow side margins of tergite 5, the yellow hairs on the scutellum and the yellow abdominal spots not reaching the side margins of the tergites. Besides, the genitalia are not conspicuously large, so that rules out E. corollae.
The best character for E. lapponicus is the sinuate vein R4+5, but this is not visibe in this picture either.

Now we are all a little wiser. My eye for detail has developed more since last year too!