Thread subject: Diptera.info :: Coelopa cf. frigida, juvenil
Posted by Volker Achterberg on 15-11-2023 21:01
#1
date: 16 Oct. 2023; location: flies on the north beach of the main island of Helgoland, island in the North Sea; a lot of seaweed/kelp at the shoreline;
many dark-brown flies with almost black thorax (probably Coelopa frigida or pilipes), but the flies on the pictures look somewhat different: more grey on thorax and also grey parts on their legs. Which species might this be? A variant of Coelopa sp.?
Thanks for any comments and best regards, Volker
Edited by Volker Achterberg on 16-11-2023 10:12
Posted by Volker Achterberg on 15-11-2023 21:01
#2
2nd picture
Edited by Volker Achterberg on 15-11-2023 21:02
Posted by Fred Fly on 16-11-2023 07:25
#3
Your specimen seems to be fresh emerged from pupa and therefore has not reached the final and darker coloration. The large specimens as from Helgoland were described as Coelopa gravis Haliday, 1833 which proved to be junior synonym of Coelopa frigida (Fabricius, 1805).
Regards
Edited by Fred Fly on 16-11-2023 07:25
Posted by Volker Achterberg on 16-11-2023 09:56
#4
Thanks a lot, Fred Fly (nice name), for your comment.
That these flies are 'fresh' specimens of C. frigida (or subspecies gravida) is a good explanation for their colouration, because there were large amounts of pupae on the beach and also some freshly hatched flies visible (see attached picture).
Best regards, Volker