Thread subject: Diptera.info :: Chalcosyrphus sp. => Chalcosyrphus valgus

Posted by Siegfried Rudolf on 17-08-2022 11:52
#1
Hello, everyone,

I photographed this hoverfly from the genus Chalcosyrphus on 08/07/22 in the Black Forest (Southwest Germany). I estimate the size at 15 mm. Unfortunately I only have bad pictures. Is it still possible to identify the species?

Greetings Siggi
Edited by Siegfried Rudolf on 17-08-2022 12:58

Posted by Siegfried Rudolf on 17-08-2022 11:53
#2
Picture 2

Posted by eklans on 17-08-2022 12:08
#3
Hallo Siggi, it's a female Chalcosyrphus valgus, I think.
"apex of the hind tibia with a short, but distinct, keel postero-ventrally, terminating in a minute spike, which is
distinctly shorter than 1/4 the apical width of the hind tibia"(, rufipes without keel or spike).
StN KEYS FOR THE IDENTIFICATION OF ADULT EUROPEAN SYRPHIDAE (DIPTERA), GLASGOW 2011 (Speight & Sarthou)
Edited by eklans on 17-08-2022 12:16

Posted by Siegfried Rudolf on 17-08-2022 12:57
#4
Hello Eric,
thank you for your determination and explanation. I am attaching another picture that shows the tibia better. You meant this spike, right?

Greetings Siggi

Posted by eklans on 17-08-2022 14:54
#5
Yes, that's the spike! And I think we can see the yellow-brown arista instead of dark brown in rufipes as well as a yellow-brown stigma.

Posted by Siegfried Rudolf on 17-08-2022 18:42
#6
great, then everything will be fine.

Thanks again,

Siggi