Thread subject: Diptera.info :: Norway: Dolichopodidae - Rhaphium caliginosum ? => appendiculatum/caliginosum

Posted by Jorn R Gustad on 08-03-2018 22:11
#1

This stowaway on a picture almost escaped my attention, until now. According to the key of d'Assis Fonseca (Handbook for the identification of British Insects Vol IX Part 5, 1978) for Rhaphium males, the third antennal segment is less than six times of the arista in caliginosum, and more than eight times of the arista in appendiculatum. If this character is considered as reliable the depicted specimen should be caliginosum. It was netted 23rd May in SE Norway, on a riverside. Both species appears in Norway.

Any help appreciated as always.

Cheers Jørn

Edited by Jorn R Gustad on 11-03-2018 23:25

Posted by Igor Grichanov on 11-03-2018 13:22
#2

Jørn, This character is more valuable:
Cercus long, bandlike; 2.4-3.1............................ appendiculatum Zetterstedt
– Cercus short, irregularly triangular, widened at middle; 2.8-3.3 ... caliginosum Meigen