Diptera.info

Posted by Jan Zwaaneveld on 26-12-2006 14:13

I found another one in my photo-archives, photographed on 6th September at Leerdam, Netherlands. Obviously a male this time, could this perhaps be the male of T. nigricornis?

Unfortunately the photos are of rather poor quality.

Thanks in advance.

Edited by Jan Zwaaneveld on 26-12-2006 14:14

Posted by kitenet on 26-12-2006 16:48

As far as I can see the trochanters are orange (not black), which should make this a male of T. atrata.

Lovely to see all these big craneflies :)!

Martin

Posted by Jan Zwaaneveld on 26-12-2006 18:19

O.k., thanks for your help, Martin!
Yes, they are beautiful creatures, aren't they?

Posted by Louis Boumans on 26-12-2006 18:38

Oosterbroek et al.'s key works also with these pictures: only 2 species have a stigmatic + an apical wing spot, i.e. Dictenidia bimaculata and Ctenophora nigriceps. The latter is not known from the NL, only from Sweden, so this must be D. bimaculata, which is also "the most widespread"and "relatively frequently encountered".

Also this species has 2 appendages on each antennal segment, against 4 in Ctenophora. Difficult to see in these pictures, but maybe this becomes visible if you enlarge the antenna in your picture..

Posted by Jan Zwaaneveld on 26-12-2006 19:28

I already wondered about the wing spots, but I could not find a reasonable alternative. I really should get that key.
I'll see if I can enlarge the antennae, but I'm afraid the photos become really hazy then (these are already cropped).

Thanks, Louis!

Posted by Jan Zwaaneveld on 26-12-2006 20:50

Two enlargements of the antennae.

Nr. 1

Edited by Jan Zwaaneveld on 26-12-2006 20:51

Posted by kitenet on 26-12-2006 23:04

Whoops, my turn to apologise for confusing things, I had forgotten about Dictenidia :o. Agree that this is bimaculata.

Martin