Thread subject: Diptera.info :: Parhelophilus versicolor ?

Posted by bonitin on 25-12-2009 13:33
#1

Hi,
I found this pretty Syrphid on the 22nd of May this year in a local Nature Reserve with lots of Wetland in Gent, Belgium.
Not sure if it is a male or female as these are tricky ones I thought?
Thanks! :)
img96.imageshack.us/img96/3610/241y.jpg
img192.imageshack.us/img192/8982/239d.jpg
img200.imageshack.us/img200/6/240ea.jpg

Posted by PIERRE MILLE on 25-12-2009 20:15
#2

Hello,

I think this looks like syrphid Helophilus pendulus and it is a female.

Posted by bonitin on 25-12-2009 21:44
#3

Hi Pierre! :)
Thanks but I don't think it is H.pendulus..
because of: H.pendulus has a black middle stripe on its face, then the bands though at first sight much alike, do differ too, the eyes of H.pendulus are much darker, also its antennae, these are orange-yellow in this fly. It also looks more hairy overall..

Posted by PIERRE MILLE on 26-12-2009 18:43
#4

Hi bonitin

I'm sorry! with us we say "I give my tongue of the cat " which means I do not see that in this case. In your opinion what is the genus name?

Posted by bonitin on 27-12-2009 00:15
#5

Hi, Pierre,

I have given the name in the thread title above of what I think is my fly; Parhelophilus versicolor.

I wanted a confirmation as there is another very much alike ;Parhelophilus fruticorum who's very hard to distingish from P.versicolor only by some subtle details one of them being the colours of the hairs on the back side of the head, behind the eyes. P.versicolor has them all yellow while P.fruticorum has a row of black hairs there, I cannot see in my fly.
The Parhelophilus genus is one of the tricky exceptions among the usual rule that females have separate eyes whiles males have them closer together or joined.
Males in this genus have them seperate too..

This is a Helophilus pendulus for you to compare ;):)
img52.imageshack.us/img52/7149/helophiluspendulus8.jpg

Posted by PIERRE MILLE on 27-12-2009 17:08
#6

Hi Bonitin,

That's interesting ! I never knew there could be exceptions to distinguish females and males. I checked and it is not easy to distinguish.

http://syrphidae.3644.co.uk/index.html
I did some research and discovered that in the genus Parhelophilus and specifically P. frutetorum ago profile of the male's head with a yellow callus and femur 3 (posterior) of the male form as a kind of bump.
I find it very informative :) !

Posted by bonitin on 27-12-2009 20:23
#7

You are welcome Pierre! :)

Posted by Andre on 28-12-2009 14:12
#8

I think this is P. frutetorum, but a possitive ID is too risky based on these pictures.

Posted by bonitin on 28-12-2009 17:40
#9

Thank you Andre! :)
So I can call it Parhelophilus frutetorum cf. I suppose..

Posted by PIERRE MILLE on 29-12-2009 00:34
#10

Thank you is very nice Bonitin ;)