---

Sochi region, 20 okt, forest, 7-8mm.
Female of Ph. subventa?

---

Almost. ;)
I think it's Phaonia rufiventris.

---

It is (= Ph. populi)?
You think so because only 1 presut ac on the image or there are another reasons?
Thank you Tony.

---

Apart from only one pair of presut acr, the characters for rufiventris are no cruciate bristles on the frons, and scutellum only narrowly darkened at base. I can't see whether there are any median bristles on tergite 1.

---

Thank you Tony.

---

Tony, are you sure that it isn't Ph. subventa?
Today at the same place I collected 5 specimens, all look like first one, all with 2 presut ac.

---

Nikita and all "The yellow-black gradient". There is a misleading couplet inFonseca?s RESL key to Phaonia females which reads at 53 (50) on page 25 ?Usually only one pair of presutural acrostichals present (occasionally one)". This means there may be two pairs of of presutural acrostichals which is sometimes the case- or one or none. We are then reliant on the colour of the scutellum to separate variegata Meigen (now subventa Harris) and bitincta Rondani ,which both have a ?broadly darkened at base scutellum? from populi Meigen (now rufiventris Scopoli) ?which has ?Scutellum entirely translucent reddish-yellow at base or at most only extreme base darkened? With these three flies, then, we cannot reliably use the chaetotaxy and are referred to colour characters which are probably not reliable either (in fact they are not according to my notes). A combination of characters give a jizz but I for one need more certainty. The question ?Do we really have three species here? is then posed.Unfortunately such confusions are often encountered in very common flies which at least subventa and rufiventris are. As long series become available variability becomes more apparent and supposedly reliable characters are shown to be unreliable. But that is science isn?t it.
Robert
P.S. Please submit the subventa photo so as to illustrate the point. Then we can do some more research.
--------------------------------------------------------------------------------
Edited by Robert Nash on 08-11-2006 11:24

---

In this case it seems that Tony was absolutely right when IDed my oktober Phaonia as rufiventris.
To compare I have photo from same place (Sochi region, Akhun mount). Thorax chaetotaxy is mostly out of focus, but colour of scutellum is clear. This male was collected and ID by Andrey Ozerov as Ph. subventa.
Nikita
P.S. I'm not sure this image is good enought for Gallery