Diptera.info

Posted by Michael Becker on 16-12-2009 16:51

Hello,

this 7mm fly is from april from the mount Teide on Tenerife (canary islands) from about 2500m. Does anyone have an idea, what it could be?

Thanks,
Michael

Edited by Michael Becker on 16-12-2009 21:38

Posted by Zeegers on 16-12-2009 17:50

looks like ornata.

Some people consider it on the Canary a separata species: quadrisetosa.

I'm not convinced.

Theo

Posted by Michael Becker on 16-12-2009 21:37

Hello Roger, hello Theo,

thank you for your answers. I looked up the genus Gonia in the Fauna Europaea, and there were four species: G. atra which seems to be different, G. quadrisetosa - thank you Theo for your explanation -, G. bimaculata, which seems to be lighter brown, if I look in the internet, and G. umbripennis, obviously an endemic or african species, of which I don't know anything.

So it seems rather sure, that it is G. ornata/quadrisetosa.

Greetings,
Michael

Posted by Jaakko on 17-12-2009 12:33

Quite dark for an ornata, at least when compared to the specimens here in north..

Posted by Zeegers on 17-12-2009 13:39

Well, yes and no.

About 5 % of the ornata are completely black.
These can mostly be found in the drawer under 'picea'

So the fact that you don't see such dark specimens, raises the question if they are really not there, or you have IDed them as picea ?

But I agree, compared with a typical ornata this one is dark. This is a common feature of Tachinidae from the Canary Isles and Madeira as well: for instance Nemorilla maculosa and Pales exsulans

Theo

Posted by Jaakko on 18-12-2009 12:45

Thanks for the pointer! The G. divisa around here are mainly black. I haven't really collected many ornata/picea, as they are all fairly common around here. The facial measures should be characteristic (and obvious when comparing), also the pollinosity on the face is different (golden/dirty in ornata, clean silver in picea), but I don't know if this is a stable feature.

Posted by Zeegers on 18-12-2009 16:52

#10

I did sent some of the black divisa to Ziegler, they surprised me as well.

We'll have to wait for his comment, and since he is working on other projects at the moment, this will take time.

the proportions of the face are - indeed - distinctive. However, be very sure to compare males with males only, females with females only !!

Otherwise you will find to undescribed species of Gonia

Gonia masculina and Gonia feminina !

Theo