Diptera.info

Posted by Dmitry Gavryushin on 26-06-2007 09:19

Shady forest (Picea/Carex/Lonicera/ferns), near a brook. Size arouns 5 mm. What I'm able to see: C with break at R1, the vein forming anal cell is convex, 2 scutellar bristles, 3rd antennal segment rounded, head round, pvt divergent, transverse vein before the middle of discal cell, MA1 and MA2 convergent with common diffuse blackish marking, body with yellowish pilosity.

Edited by Dmitry Gavryushin on 14-08-2007 06:28

Posted by Iain MacGowan on 26-06-2007 09:55

Hi Black

Yes this is a Stongylophthalmyid - the little family with a big name. there are only 2 Palearctic species S.ustulata which I think thisa is, and the rarer S. pictipes which I have only taken specimens from Finland and Russian Karelia, from memory it has darker setae on the thorax and a more pronounced apical cloud on the wing than ustulata. Both species are part of the saproxylic Diptera fauna associated with old aspens ........... Iain

Posted by Dmitry Gavryushin on 26-06-2007 10:05

Many thanks Iain - I spent quite a lot of time on it trying to find a match among Psilidae...

Posted by Kahis on 26-06-2007 12:09

The two species are illustrated here: http://www.elisan...a/strongy/

I have collected S. pictipes a few times, always on the trunk of a recently fallen large aspen. The flies look and behave like clusiids; males run rather slowly around and flash their wings to flies of similar size. On a suitable tree males can be numerous.

S. ustulata is definitely not an aspen-only species. It is locally common in humid, rich forests, especially along forest streams (exactly as you describe). Unlike S. pictipes, I have never found this species on aspen trunks. I've often caught it on the leaves of Prunus padus.

Edited by Kahis on 26-06-2007 17:52

Posted by Nikita Vikhrev on 30-06-2007 09:29

I also found this fly in Mosc reg, 2 copulated pairs was observed on leaves of Tilia cordata near old pond.
Sorry, only bad image:@

Posted by Dmitry Gavryushin on 06-07-2007 13:29

Yesterday I've found another male (4 mm) at basically the same location (on the other side of the railroad). Got some pictures good enough fot the Gallery ;).

Posted by Dmitry Gavryushin on 22-07-2007 21:29

#10

Today I was lucky enough to find a location with lots of these. It was around 5 p.m. at Ozhigovo station, I found a big aspen (around 50 cm in diameter) that once broke at the height of ca. 6 m and fell on the ground. There were dozens of S. ustulata, mostly females, and they were laying eggs (I think a couple is visible in the left picture). It was not only bark of the trunk but also big branches. Some performed specific movements, slowly turning left or right, like screwing the bark.

Edited by Dmitry Gavryushin on 22-07-2007 21:32

Posted by jorgemotalmeida on 22-07-2007 23:59

#12

awesome photos!!! this fly is such a beauty! I hope to find them near aspen...as well. :D

Posted by Dmitry Gavryushin on 14-08-2007 05:53

#13

August 11 and 12, other fallen aspens, but they are still here. Some illustrations of their egg-laying habits. I just wonder what makes them compete with each other for a certain patch of bark with square metres of same bark around? Probably some specific conditions (humidity, temperature, presence of some fungi or eggs laid by other females)...