Thread subject: Diptera.info :: Tachinidae

Posted by neprisikiski on 30-12-2010 22:29
#1

Hellow, I have a question concerning the genus Exorista. If Exorista rustica species group always has three postsutural dorsocentral bristles? Because I have several specimens very similar to these, they are females, but with four bristles. Or may be they are Exorista glossatorum? Sorry for bad photos. Thank you in advance.

Edited by neprisikiski on 30-12-2010 22:35

Posted by neprisikiski on 30-12-2010 22:36
#2

Head

Edited by neprisikiski on 30-12-2010 23:03

Posted by ChrisR on 30-12-2010 23:02
#3

Yeah, I think 3 post-dc pretty much defines the rustica group. If I saw an aberrant with 3 on one side and 4 on the other then I might still call it rustica-group but if it clearly has 4 on each side then it would have to be something like glossatorum I think :)

Posted by neprisikiski on 30-12-2010 23:04
#4

Thorax

Posted by neprisikiski on 30-12-2010 23:11
#5

Thanks for your comment Chris, but next what I have noticed is that there are two types of specimens with four post-DC; one of them have D-discal bristles and their vertex as wide as an eye, like in Exorista rustica females; others (you see it from the photos), have no D-discal bristles and their vertex wider than an eye, like in Exorista mimula females!

Edited by neprisikiski on 30-12-2010 23:27

Posted by ChrisR on 31-12-2010 01:44
#6

Interesting observation ... how do both forms key in the Central European key? I can't see the abdominal dusting so I can't run it here myself. :)

Posted by Zeegers on 31-12-2010 14:00
#7

I have one aberrant male Exorista rustica group (based on genitalia) with clearly 4 post DC on both sides.

However, in this case, you really might have something else. The lack of discal setae in females rustica is unusual in Central Europe. So that makes 2 aberrant features combined.

I have no experience with glossatorum, so I can't help there.

Find the male !!


Theo


Posted by neprisikiski on 31-12-2010 15:50
#8

Chris, both forms could be identified as Exorista glossatorum, but P. Tschorsnig gives very little characters here, therefore I have feeling that number of post-DC can be not a stable character.
Theo, your information is important for me, thank you very much. But how you was sure about Exorista rustica group if you have no experience with Exorista glossatorum, I didn’t see figures of genitalia of this species?
Happy incoming New year, by the way ;)

Posted by Zeegers on 31-12-2010 17:48
#9

Glossatorum males have black hairs, no golden ones, on the syncercus.

There is a full description of glossatorum in Mesnil in Lindner, however, hidden under the name 'baranoffi Wainwright'.

Hope that helps


Best wishes for 2011


Theo