29 July 2011

A Hoverfly

 I noticed this hoverfly yesterday while out at Pelenna yesterday. Following some rather length keying out last night I came to the conclusion that it is Chrysotoxum elegans. Looking at the local records of this species it has been recorded, somewhat irregularly, near the coast so this would represent more of an inland sighting. I don't have much experience with this species and was wondering whether any experts out there could confirm the identity of this hoverfly?
Following a day out with Ian Tew, Tristan Bantock and Ray Wilson we were able to look this hoverfly from the photos I took. The feeling was that the photos don't allow for a definitive identification but that to label this one Chrysotoxum arcuatum cf. was not unreasonable. In fact Ian Tew photographed this species earlier this year, in May, at Afan Argoed on the link below. Some further info in comments.
Chrysotoxum arcuatum

4 comments:

Martyn said...

Great photos Mark. I had to key this one out as well and got as far as C.elegans/verralli, but can't make my mind up as i,m leaning towards verralli, which as far as i,m aware has been recorded in Wales. You could upload the picture to the "Hoverfly recording scheme" website and they'll be only to happy to confirm ID for you. Unless somebody else on here can confirm.

Martyn said...

That should read "hasn't been recorded in Wales"....Doh!

Mark Hipkin said...

Thanks Martyn. Yeah, I got to the same quandary (elegans/verralli) and although I can't see any pale hairs on the scutellum, the photos are not quite good enough to be absolutely sure. I've posted a link via on the hoverfly recording scheme so hopefully we'll hear some news from them before long.

Mark Hipkin said...

The important area to focus on is the relative lengths of the antennal segments. In C. arcuatum segment 3 is twice at long as segment 1 + segment 2
In the other similar species seg 3 = seg 2 + seg 1
One of the other key points when considering C. arcuatum is that it has dense dark hairs on the eyes. However, this feature can be very difficult to pick up from photos. Having looked at a few online this seems to be especially the case with female C. arcuatum.