Thread subject: :: 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?

date: 07/07/2009

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.

Specimen 1:

Here is a photo of the middle left tibia viwed from behind:

Specimen 2:

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.