Thread subject: Diptera.info :: A small fly at my balcony (2)
#1
May 23, 2006.
Size 3mm.
Posted by
Kahis on 23-05-2006 20:52
#3
It's a tachinid, probably tribus Siphonini but not
Siphona as it does not have a long proboscis. Pwrhaps
Actia?
#4
Thanks a lot Kahis,
I never met (in my Diptera-conscious time) such a small Tachinidae.
Posted by
ChrisR on 23-05-2006 22:35
#5
Definitely a tachinid. I'd kind of agree with Kahis about
Actia but it might also possibly be something like
Phytomyptera sp. or
Paracraspedothrix montivaga. I will compare them to some specimens here and come back to you

Posted by
ChrisR on 24-05-2006 09:58
#6
After checking my specimens I think it is an
Actia - perhaps
infantula, but I can't see the katepisternum clearly enough to be sure.
Replying to Black's comments on its small size: There are several small species of tachinid in families like
Actia ,
Phytomyptera and
Paracraspedothrix. These have correspondingly small hosts, like micro-moth larvae in fungi. Of course, if the host is extra small and doesn't eat well then the resulting tachinid fly is even smaller than normal

Edited by
ChrisR on 24-05-2006 10:12
#7
Thanks a lot Chris,
I've just checked what on Earth that katepisternum is (with Syrphidae as an example, http://home.hccnet.nl/mp.van.veen/KEYS/bodypart.htm) and there's more lateral views available, so maybe I'll post an additional image when I'm (finally) home.
Regarding small size, now I remember recent discussion here about Tachinidae spp. size variations, yet I presume that flies of the mentioned genae are typically/invariably small...
Posted by
ChrisR on 24-05-2006 17:45
#8
Yes, if you have any additional images please send them - they are very good

Also, if you can see a way of enlarging the katepisternum so that we can see the bristles clearly then that would help.
Thanks
Posted by
Zeegers on 24-05-2006 21:01
#9
I think it is Peribaea tibialis:
Male Actia infantula has larger third antennal segment.
It seems to be a male (?).
Moreover, the lowest sternopleural bristles seems to be thick.
Other species of Actia can be ruled out by the lack of bristles on the CU-vein.
As can very well be seen in the picture.
Theo Zeegers
Posted by
ChrisR on 24-05-2006 21:53
#10
Ahhh, good work Theo - we don't have
Peribaea tibialis here so I am not familiar with it.

Posted by
Zeegers on 25-05-2006 09:30
#11
Thanks
still, a additional photo showing either the sternopleuron or the wing would be useful.
I consider the ID provisionally.
Theo
#12
Thanks again Theo and Chris,
Here's the best combined crop of lateral views I was able to make.