Thread subject: Diptera.info :: Muscidae or Tachinidae?

Posted by Gerard Pennards on 08-04-2005 20:43
#1

Dear all,
THis one I found near Amsterdam in the Netherlands, it was about 5 mm in lenght.
It was sitting on a tree trunk, basking in the sun.
I first thought it was a kind of Muscidae, but I am not sure anymore!
The specimen seems to have a Tachinid like wing venation, and a very broad frons.
Can somebody give me a clue?
Thanks in advance,
Greetings,
Gerard
www.diptera.info/forim/5-0243-1.jpg

Edited by Gerard Pennards on 08-04-2005 20:44

Posted by Laurens van der Leij on 08-04-2005 23:08
#2

Could it be Pollenia spec. (Calliphoridae)?

Posted by Zeegers on 10-04-2005 20:06
#3

Hoi Gerard,

Definitely a Tachinid.
Difficult to determine based on the picture.
Given the circumstances: early spring on tree stems an educated guess would be:
Campylochaeta praecox.

This species is easily recognized by the ocellar bristles (the strongest bristles between the ocelli) being reclinate (= curved backwards). In nearly all Tachinidae they are proclinate.

So, let me know.

Theo Zeegers

Posted by Gerard Pennards on 10-04-2005 21:46
#4

Thanks, Laurens and Theo.
I thought about Pollenia myself, but after I while a realised that Pollenia looks different, and then I started thinking about Tachinidae.
Unfortunately I didn't catch it, it escaped after I made the picture.
Maybe I will see another one the coming days, then I will try to catch one!
So for now I will keep up with the name Theo provided!
Greetings

Posted by Gerard Pennards on 10-04-2005 21:53
#5

And a more detailed picture of the head.
Does it help?
Greetings

www.diptera.info/forim/5-0243-2.jpg

Posted by Zeegers on 18-04-2005 20:02
#6

The ocellar bristles appear to be proclinate, so much for Campylochaeta !
My last guess (I know, three is a charm, I'm just trying to keep the level just a little bit of scientific hear): it might be Cyzenis albicans.

Features: tibia reddish.
On the frons: parafrontals (the lateral stripes between ocelli and antennal base) with 1 pair of strong proclinate setae (in both sexes !)
This lack of sexual dimorfism is quite special in Tachinidae: in 90 % of the species the females have 2 pairs of proclinate setae on the parafrontals, whereas males have none.

Otherwise, I pass.


Theo Zeegers