Diptera.info

Posted by ChrisR on 20-12-2009 11:39

Originally I had this one down as a female Dinera ferina but the more I look at my Billaea kolomyetzi, the more I think this is perhaps a female of that species. The antennae are short-hairy, not 'plumose' in the true sense so that fits B.kolomyetzi but the excavation on T1+2 seems the same/similar to the D.ferina I have here. But both fore tarsi are missing so I can't check that against the head height. Also, the hind tibia has no bristle comb but T&H implies that some female Billaea don't ... has anyone got any good ideas? :)

Edited by ChrisR on 20-12-2009 18:15

Posted by Zeegers on 20-12-2009 13:50

I agree, it looks like Billaea.

Actually, it looks very much like the female Billaea I recently sent to Tschorsnig. There seem to be too much bristles on tergites for kolomyetzi. What happens if you run it though my key ?
Only 2 STPL, distinct black hind margins on tergites and I think dark triangles as well, no comb as remarked....

And 'clearly 5 vittae' on mesonotum, for what it is still worth

Theo

Posted by ChrisR on 20-12-2009 13:59

Well, again it all hangs on the '4 clear dark vittae' ... if you read it that the middle one is too faint and indistinct (because it is very hard to see at some angles) then it runs to B.kolomyetzi but if not then it runs on to B.steini again - like my previous B.kolomyetzi. I'd have to bet on it being B.kolomyetzi again because it was caught at the same location as the male, one day later :)

My female has very short arista hairs; very indistinct central facial ridge; 2 STPL on both sides; no T1+2 marginals; the dusting on T3 is restricted to the anterior 1/3 dorsally and the anterior 1/2 laterally; T4 is more extensively dusted with dark circles around the base of the marginal bristles; there is also a faintly dusted central line running from T3-T5.

Posted by Zeegers on 20-12-2009 17:55

Maybe kolomyetzi is rather sexual dimorph.

I don't know of anyone who actually saw the female of kolomyetzi, except for Kolomiets and I didn't see his article.
So let's wait for Tschorsnig

Theo

Posted by Zeegers on 02-04-2010 20:57

I got a message from H.P. Tschorsnig (the real expert).

He agrees this should be the female of B. kolomyetzi.

Very peculiar the presence of marginal setae is sexual dimorph !

I'd need to revise my key.

Theo

Posted by ChrisR on 02-04-2010 22:07

Wow - excellent news Theo - thanks for updating us on that! :) I was going to send it to Peter but I won't risk the post, if he is happy with the ID. :D