Thread subject: Diptera.info :: Chrysotoxum?

Posted by kobra on 09-08-2014 09:25
#1

I would like to know which species this is.

It concerns this sighting:
http://observado....w/87031917
identification uncertain Chrysotoxum octomaculatum observed at 2014-07-21 BRD - Haßberge (Landkreis)

observado.org/fotonew/0/7174780.jpg

observado.org/fotonew/2/7174782.jpg

thanks in advance
Koenraad

Posted by ValerioW on 09-08-2014 11:26
#2

Right ID! It's a male C. octomaculatum

Posted by kobra on 10-08-2014 09:12
#3

Thank you for the confirmation, Valerio.
Ciao,
Koenraad

Posted by Stephane Lebrun on 10-08-2014 09:26
#4

Sorry but I disagree, this is not C. octomaculatum : the 3rd antennal segment is well too long and the rim of tergites 3 & 4 is not yellow at level of black front bands. Should be like in the last pictures of this page :
http://cyrille.du...illus.html

Posted by Mark van Veen on 11-08-2014 07:49
#5

C. cautum, I would say.

Posted by kobra on 11-08-2014 09:36
#6

Thank you for all the info.
OK, no C. octomaculatum.
So maybe C. cautum or fasciolatum?
This may stay uncertain with these pictures, I guess.
Regards,
Koenraad

Posted by ValerioW on 11-08-2014 18:34
#7

Stephane Lebrun wrote:
Sorry but I disagree, this is not C. octomaculatum : the 3rd antennal segment is well too long and the rim of tergites 3 & 4 is not yellow at level of black front bands. Should be like in the last pictures of this page :
http://cyrille.du...illus.html



I enlarged the photo and I'm totally agree. 3rd antennomere is pretty long. I didn't check the photo for first steps in ID, assuming kobra did already, sorry.

Posted by ValerioW on 11-08-2014 18:41
#8

Mark van Veen wrote:
C. cautum, I would say.



Without considering wings, cautum can be quite straight, flat abdomen fits. But wings are too much dark on the outer half of front margin. Eyes'pilosity can be a useful trait, but I cannot discriminate it with this resolution.

Posted by ValerioW on 11-08-2014 18:44
#9

kobra wrote:
Thank you for all the info.
OK, no C. octomaculatum.
So maybe C. cautum or fasciolatum?
This may stay uncertain with these pictures, I guess.
Regards,
Koenraad



Wing colours are fascicolatum-type, and enlarging the head it appears (please, would you like to check and confirm?) that 3rd antennomere is longer than 1+2. So cautum can be ruled out. I'd say C. cf. fascicolatum

Posted by kobra on 17-08-2014 10:36
#10

Hi again,

I have now cropped a picture of the head - I am not sure that it is clear now, since I am not a specialist, so maybe someone can confirm now?

observado.org/fotonew/6/7236656.jpg

Regards,
Koenraad