Help with Hoverfly ID?

[jezlee]

Hello all - unfortunately, this is the only pic I've got - but I'm struggling with this one. Is it one of the Platycheirus??

[Geoff F]

Yes one of the Platycheirus.

Did you want more?

This is a tricky one. I'm tempted to say P. clypeatus but the spots are a bit pale and the black area on the hind femur extends further towards the tip than is normal.

However, I can't easily fit this specimen into any other species.

Some more opinions would be welcome.

[JRsbugs]

I've had a male Platycheirus scutatus recently, then I had a female which was confusing me as the pics I was seeing led me to another species.

When I compared it with the female P. scutatus on this site it fitted well! This looks like my female, so I'm fairly confident that's what it is. The site linked to belongs to a dipterist, I found it linked to while searching on diptera.info.

Janet

[Geoff F]

But if you compare the spots on tergite 2, Janet, they are rather smaller than tergite 3 for P. scutatus, and usually hemispherical in shape.

This specimen has rather large tergite 2 spots, which is one of the items which confused me and eventually led me to consider P. clypeatus. Otherwise, as far as I am aware, the two species are quite similar.

But I'm not really sure either way on this specimen.

[JRsbugs]

Actually I see now this one has an extra set of spots to the one I have!

Need to check it again, but with only one angle it's not ideal. A side view of the face profile can help.

[jezlee]

Why do I always get the confusing ones??

Thanks as usual for your input, Janet and Geoff, it's always helpful to get someone else's views on these things. Unfortunately, it IS the only shot I've got, and I was struggling to match it myself to any one species ....

[JRsbugs]

The shapes look more like P. peltatus, but that protruding face looks like P. manicatus!

I had manicatus on the 10th, it was a tiny thing and very pale, silvery looking.

[jezlee]

Just to throw another spanner in the works, how about P.occultus?

[JRsbugs]

Originally Posted by jezlee

Just to throw another spanner in the works, how about P.occultus?

No.

The shapes do match P. peltatus, I can only assume the face angle is making it look more protruding than it is.

What do you think Geoff?

[Geoff F]

I think that P. occultus actually does appear quite likely.

P. peltatus belongs to the group which have slight yellow markings on the underside of the third abdominal segment. Which I think is absent here. Also, the spots tend to be broadest at the inner edge. Somewhat similar to Melanstoma although not as pronounced as that species.

This specimen appears to have the leading edge of the spots decreasing as it reaches the abdomen edge; which is correct for P. occultus. The area directly behind the ocellar triangle does look rather dark which is another pointer to P. occultus.

But we really need a good view of the hairs on the front femur to be sure of anything here.

P. occultus was originally considered a variation of P. clypeatus but has recently been placed as a separate species.

But females of these species are very similar and, just to make things even harder, there can be considerable variation between individuals of the same species. And Mr. Stubbs didn't show an illustration of P. occultus so I'm just working on the key and description.

The only downside of a possible P. occultus identification is that I think the spots on tergite 2 of Jezlee's specimen may be too large, I don't know how variable this species is. Alternatively we probably return to clypeatus, although the angle of the leading edge of the spots is important here.