The Society for the study of flies (Diptera)

Hi,
I think it must be segnis as there does not appear to be any break in the orange-red mark on the abdomen. X. tarda has a dark mark breaking up the red mark.

Hello Janet,
In females of X tarda there should be a darkening at the rear of the second tergite and the abdomen is quite noticeably bulbous shaped in comparison to the parallel sided abdomen of X segnis.

X tarda is very scarce. The recording scheme has only 16 post 2000 records for the species. By comparison X segnis is amongst our most frequent hoverflies (711 post 2000 records), so the odds are firmly in favour of X segnis - particlularly in the absence of the key features for tarda.

I have only ever seen a single specimen of X tarda, collected by someone in Worcs, and it is quite a different looking fly from X segnis so I am 99% confident about your's being segnis. I'm always reluctant to say 100% confident from photos though!

Hi Janet,
Sounds like a very good location where you live. I worked in an office set in old estate woodlands until recently and it was very good for a good number of scarce species, so you may yet get a definitive X tarda.

Hopefully so Nigel.  I'll certainly be posting it if I find one which can be clearly said to be that species.

One day when I managed to get all my flies together and properly identified I will have to submit all my records, I have some good ones!  It's an ongoing process though, and I snap everything, not just flies so I'm being kept rather busy.

I agree that it is segnis. But if you have any ancient woods with aspen, check out sunlit foliage for tarda. It is not too rare in Warwickshire once you have worked out which woods have aspen.

Falky

In Warwickshire it is specifically associated with Aspen (and as the county tree registrar I check a lots of other poplars). Suprised it does'nt seem to use Grey Poplar (which is supposedly 50% Aspen), but I'd like to check that matter further when I get time. Saw quite a few tarda today at Ryton Wood resting on foliage of Aspen regrowth in coppiced areas. The association is so strong I sometimes wonder if tarda is attracted by the balsamic smell of aspen. But other poplars are known to support things like the ulidiid Myennis Octopunctata, and fallen Grey Poplar trunks in rivers and streams appears to be used by Chalcosyrphus eunotus her in Warwickshire (possibly Tanypeza too).