Thread subject: Diptera.info :: Spearhorn ID? (Ketton Rutland)

Posted by Gman on 19-07-2022 23:35
#1

Hi All

Came across a number of these hoverflies that I haven't seen before
I think they are Chrysotoxum festivum (Hook-barred Spearhorn).

Could some confirm or put me straight please?

Yours, Gareth

Posted by Sundew on 21-07-2022 01:55
#2

With the distinct downturned bars on segments T2-4 and wholly orange legs, this is a female of Chrysotoxum festivum indeed.
It pays to look at the key https://books.goo...&hl=de, however. It lists the most important characters, starting with the length of the three antennal segments. If I photograph a Chrysotoxum, I always try to get a good shot of the antenna. Then, a lateral shot of the thorax should show if there are yellow spots and how the femora are coloured. One picture is not enough for identification in most cases!
Regards, Sundew

Edited by Sundew on 21-07-2022 01:56

Posted by Gman on 21-07-2022 15:37
#3

Hi Sundew

Thanks for the confirmation and information. Normally I have40-50 pics per invidual hoverfly but these hoverflies stayed in the medium grass,
in shade on one of the hotest days on record. They were constantly on the move and impossible to get moe helpful angles.

I struggle with keys, I usually use pictures from variouis books like Ball & Morris, and also Steven Falk's Flickr page - an amazing resource!

Thanks again, Gareth