Thread subject: Diptera.info :: Tachinid of today 1: Gonia picea

Posted by Sundew on 15-03-2020 22:08
#1
Hi,
Today I saw three Tachinids in a flowering population of Draba verna (formerly Erophila verna), Brassicaceae. The location is in southwestern Germany, about 20 km west of Stuttgart.
The shown species should be Gonia picea as to early flight time and colour of the abdomen. Do you agree?
Thanks, Sundew
Edited by Sundew on 16-03-2020 17:34

Posted by Sundew on 15-03-2020 22:09
#2
More pics.

Posted by Zeegers on 16-03-2020 11:27
#3
Yes.

Theo

Posted by Sundew on 16-03-2020 17:37
#4
A cool fly, nice to know it - thanks for confirmation! BTW: how can we tell apart the sexes? The "big feet = male" rule of thumb doesn't work here...

Posted by Sundew on 16-03-2020 18:54
#5
Meanwhile I found a paper by Zeller (1842) who states that the length ratio of the antennal segments 2 and 3 is decisive.
In males, the 3rd antennal segment is about four times as long as the second.
In females, the 2nd antennal segment is about half as long as the third.
If so, I have photographed a female.

Posted by Zeegers on 16-03-2020 19:08
#6
Yes, all is correct.

Theo

Posted by Sundew on 16-03-2020 19:44
#7
Great - it is a delight to gather knowledge. Thanks again!