Thread subject: Diptera.info :: Phaonia rufiventris

Posted by crex on 05-11-2006 23:14
#1

From midwest Sweden 2006-10-12 ... (missing text where I try to guess the family, ehh, Muscidae*) ... Id? Thanx!

* It looks a bit like the yellow Muscidae in the gallery

Edit: Changed subject (Fourlegged yellowbelly)

Edited by crex on 08-11-2006 10:59

Posted by Nikita Vikhrev on 06-11-2006 12:46
#2

I am not sure.
I think it is Muscidae, but neither Ph. pallida, nor Thricops.
I think it is Phaonia, may be Ph. subventa.
Nikita

Posted by crex on 06-11-2006 21:48
#3

Thanx Nikita!

Posted by Nikita Vikhrev on 06-11-2006 22:04
#4

Just wanted to write you that I looked at my collected Ph. subventa and didn't find any with such a yellow pleuras. May be yours is very fresh?
Wait for Kahis or Tony:(

Posted by Robert Nash on 07-11-2006 12:57
#5

Entirely translucent yellow-red scutellum and extensively yellow-red humeri, sides of dorsum and pleurae indicate rufiventris Scopoli = populi Meigen . A confusing statement in Fonseca's key reads Usually only one pair of acrostichal bristles present (occasionally one) Does this also mean sometimes two? If this is rufiventris it is a very useful and very sharp :p:p photo for the gallery
Robert

Edited by Robert Nash on 07-11-2006 12:59

Posted by crex on 07-11-2006 13:39
#6

Thanx Robert, I will submit to the gallery alright. If you need magnification of some special part of the fly let me know and I'll see what I can come up with ...

Posted by Robert Nash on 07-11-2006 13:44
#7

Maybe better wait for confirmed id. I'l get back to you.I mailed around. Robert

Posted by Tony Irwin on 07-11-2006 18:05
#8

Crex - could we have an enlarged view of the head, please?

Posted by crex on 07-11-2006 19:12
#9

Hmm, a poor photo ... sorry.

Posted by crex on 07-11-2006 19:20
#10

It was so underexposed so I didn't realize I also had this dorsal view of the same fly. Ermmhh, I'm still struggling to manage my DSLR and new ringflash ... :(

Posted by Robert Nash on 08-11-2006 09:56
#11

Good news.Adrian Pont replied "Yes, that looks like Phaonia rufiventris. You can see the "Phaonia-bristle" on the hind tibia. The thorax is too dark to be pallida and too yellow to be subventa, so I am sure that you are right it naming it as rufiventris.":p:p. We are slowly building up a photo id library for Muscidae and other suspects. So keep up the good work. But expect some disappointments if you don't have a specimen.And if it's Anthomyiidae even if you have.Robert

Edited by Robert Nash on 08-11-2006 09:57

Posted by Nikita Vikhrev on 08-11-2006 10:34
#12

Submit in Gallery, Crex!
I'll submit my Ph. subventa (not as good image as I'd wish) and we'll have all yellow-black gradient: pallida-rufiventris-subventa!
Nikita

Posted by crex on 08-11-2006 10:44
#13

Thank you for all efforts Robert & Nikita! And also a big thanx to Adrian Pont if he read this ...

Posted by Robert Nash on 08-11-2006 11:19
#14

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