Hoverfly ID

Tormentil · #1 (**permalink**) 19-06-2010, 07:55 AM

Is this Chalcosyrphus nemorum ?

Geoff F · #2 (**permalink**) 19-06-2010, 07:10 PM

That is a tricky one. And I suppose it would be a waste of time to ask for a clear view of the abdomen!

Without that, my initial guesses are that the abdomen appears a little on the long side for C. nemorum. Generally a woodland species.

Tropidia scita is worth considering as we can't tell if there are strong abdomen black cross bands or not. Generally likes wet areas in the South.

But the faint pale stripes along the thorax remind me of Syritta pipiens; and from what I can see of the abdomen spots, they do appear to be rather long with rounded inner corners. The longish abdomen would also fit better for me.

But, as I said, I think that without a clear view of the abdomen we are just guessing here. Although one of the real experts may be able to offer some firmer suggestions.

Tormentil · #3 (**permalink**) 19-06-2010, 07:15 PM

If it's any help, it was at Woodwalton Fen. And that's the only shot I got!

Geoff F · #4 (**permalink**) 19-06-2010, 07:56 PM

I've tried to run this through the ID keys but, like so many species, it comes down to a personal opinion on the shape of one item; in this case the hind femur shape. And, of course, a photograph only gives one angle with an imperfect view.

The 'pinched' area on the thorax and it's rather extensive grey sides, still makes me think about S. pipiens as the most likely. But from what I can see of the hind femur, I wouldn't rule out the possibility of Tropidia scita, especially as it was in a wet area on the East of England.

One for Roger Morris, or a similar specialist I think.

ps. Of course, the easy answer is for you to go back and get another photo with the wings open and a clear view of the abdomen.