Diptera.info

Posted by Stephen R on 16-02-2010 22:04

I have quite a few photos of P. montivaga from last summer, and I agree this looks similar; but I also see a few differences:

a: in this fly the r-m crossvein seems to be at an oblique angle. In my photos it is short and straight across.

b: There seems to be a prominent bristle at the costal break. I can't see this in my pictures, though there is a series of short bristles.

c: In my photos the abdominal bristles are fewer and more regularly spaced (not more than 4 strong ones on T5, for example [EDIT: not true, Ive found one which shows more]), and the pale bands always seem to extend closer to the median line, often appearing continuous.

The other thing I am suspicious of is the size - I have not managed to achieve such depth of field for a live 3mm fly in natural light. Maybe I'm just jealous :

Another edit: Oh, I don't know, maybe this is all rubbish. Sorry I spoke:(

Edited by Stephen R on 16-02-2010 22:42

Posted by Zeegers on 17-02-2010 08:36

It is always good to critically review suggestions, especially since mine was only a first impression.

The point of the pale bands bothered me slightly, but I think the light is very insufficient to really be able to judge it. Your other points are a minor concern, in my opinion.

As second glance, I still think it might be Paracras...
Arguments pro

It is a male (given the size of antenna) with broad vertex. Rather unusual

The arista is thickened on basal half or more.

The wing and bristles on scutellum suggest Blondeliini.

Still, it is only a second guess and no ID

Theo

Posted by Zeegers on 17-02-2010 22:27

I got my Ph.D. on this lemma

'Dubito, ergo sum'

Only 20 years later I did learn that Augustinus beat me with 1600 years.

So keep questioning the answers, if you please

Theo

Posted by Stephen R on 17-02-2010 23:36

Thank you. I will continue to risk embarrassment! 'Da mihi dignitatem, sed noli modo.' It's a bit late to start worrying about chastity and continence ;)

Stephen.

Posted by ChrisR on 18-02-2010 09:33

I have found that the realization that one can never be 100% certain (about almost everything) is a very liberating thing :D

In addition the fact that we cannot be certain shouldn't prevent us working on stuff ... I have made a career of it! ;)

Posted by Zeegers on 19-02-2010 17:22

#11

The though crossed my mind.

It is NOT A. blanda, and if it was 3 mm., it can't be.
But we know that estimates of length are very unreliable.

On the other hand, relative to the leave, it seems very small.

So, it might be Admontia, but it might be Paracras. as well, as far as I can see it now.

Theo