Thread subject: Diptera.info :: Syrphidae, Chrysotoxum sp., female, sept, 9th 2014 --> C. festivum/vernale

Posted by ThorstenRoeder on 10-09-2014 18:10
#1

Dear all,

unfortunately just one bad shot:-(. Then the fly took off...what a pity...
I nevertheless tried the key of Mark van Veen.
Neither length relation of antennal segments is distinctly visible from that angle, nor do I have a rear aspect, But with exclusion I reached to either C. cautum or C. festivum. I cannot really decide, if that dark parted field on left wing is the real dark wing spot (that C. festivum should have) or if it is just light fake. But this dark "stain" there still stays dark when photo is strongly brightened. And the fly seems to have entirely yellow legs, like C. festivum (?) I saw a C. cautum male for sure once in my garden this year.

So, my only chance is, that one experienced here perhaps gets a "jizz", when looking at it. What do you think?

Size seemed to be within"normal range" for this genus to me, e. g. nothing extraordinary small or large.

Garden, northern upper rhine rift, Germany, resting for a view seconds on an ivy leaf, half in shadow (no flashlight used), on wall, about 6 feet above ground.

Thanks in advance for reading this.

Best wishes, Thorsten

Edited by ThorstenRoeder on 13-11-2014 16:35

Posted by Ectemnius on 28-10-2014 14:49
#2

Hello ThorstenRoeder,

This is a female C. festivum/vernale. The markings on the abdomen and thorax point to these two species. Looking at the sides of the thorax the yellow stripe on the anterior side seems to be interrupted. That would make it C. festivum.

Greetings,

Ectemnius

Posted by ThorstenRoeder on 13-11-2014 16:34
#3

Hello, Ectemnius!

Thanks a lot for your answer!
I tried to enlarge the relevant thorax side part, but - senseless - it is not better visible anyway then:-(
So, maybe, quite late flight time (sept, 9th) - which I mentioned above just in topic line unfortunately , but not in the text - could as well make C. festivum more probable (?).

Best wishes

Thorsten