Thread subject: Diptera.info :: Besseria sp.?
Posted by Rui Andrade on 14-07-2009 19:20
I saw many of these tachinids in dunes in Viana do Castelo, North of Portugal. It reminds me of Besseria, could that be correct?
Posted by jorgemotalmeida on 14-07-2009 19:21
i think so imho.
Posted by Zeegers on 15-07-2009 19:54
Definitely an excellent picture of a Besseria.
Difficult genus, might be either dimidiata or reflexa
Posted by Rui Andrade on 15-07-2009 20:30
Thanks Jorge and Theo.
Theo, what would you need in order to decide between one of them?
Posted by Zeegers on 15-07-2009 21:59
That will be very difficult.
I'll check and come back to you.
Posted by ChrisR on 16-07-2009 09:52
Just a quick quote from T&H:
4. Peristome dusted white. Frontal stripe with a yellow ground colour. Middle tibia with 2 inner bristles, the upper often much weaker. Males: tergite 5 with short upright hairs; cerci-surstyli complex 2 - 3x as long as the epandrium, roof-like developed, inside with a ring of yellow scale hairs. Females: tergites 2 and 3 ventrally with a spine field.................dimidiata Zett.
- Peristome at least in its front half shiny black. Frontal stripe in the ground colour black. Middle tibia with 1 inner bristle. Males: tergite 5 dorsally hairless, smooth and shiny; cerci and surstyli a little shorter than the epandrium, without yellow scale hairs. Females: spine field only present on tergite 2..............reflexa R.D.
So a closer view of the legs or head at different angles would be useful :)
Edited by ChrisR on 16-07-2009 09:53
Posted by Rui Andrade on 17-07-2009 15:54
Thanks Chris:). I have some specimens with me, later I'll have a look at them.
Posted by Zeegers on 17-07-2009 20:45
This was what I had to look up, thanks
This clearly suggests reflexa.
Still, a lateral headshot would be useful
Posted by Rui Andrade on 20-07-2009 19:37
Ok, finally some photos. They show two different specimens.
Here is a photo of the middle left tibia viwed from behind:
Middle left tibia viewed in this case from the front:
Posted by Zeegers on 21-07-2009 21:10
so, definitely dimidiata and not reflexa.
The black on the gena is missing, moreover, the erect hairs on tergite 5 of the male (first specimen) is excellently illustrated !
Posted by Rui Andrade on 21-07-2009 21:49
Thank you for your help Theo! I think it's a new species for Portugal. The only two species known so far are B. lateritia and B. zonaria.
Posted by Zeegers on 22-07-2009 17:56
Portugal has been poorly studied (uptill now, of course, guys !) and it is known from Spain. I can't say I'm surprised.