Thread subject: Diptera.info :: Tachinidae

Posted by Susan R Walter on 03-03-2007 21:20
#1

But might be Sarcophagidae...

I've opted for Tachinidae because it has bare arista and no sign of little bristles on the hind coxae, so presumably not Sarcophagini. Eyes bare, legs black, abdomen dusted in a chequerboard pattern, thorax strongly striped, M and Cu with appendices where they bend. There is a long single bristle in the discal cell, laying across the cross vein at right angles. 7mm.

From 17 June 2006, east London cemetery park.

Posted by Susan R Walter on 03-03-2007 21:21
#2

Another view.

Posted by Zeegers on 03-03-2007 22:13
#3

It looks like a Miltogrammine, possibly Amobia (long shot !)
can't see the head bristles clearly enough./

Small chance it's Tachinidae (Meigenia ?)
SO check postscutellum first


Theo

Posted by Susan R Walter on 04-03-2007 16:42
#4

Hmm - tricky. It's got *something* under the scutellum, but not like the bolster shaped appendage pushing up at the scutellum that tachinids have. The scutellum appears to sit up proud from the abdomen and from 'subscutellum' or whatever it is which is sitting flat and neat on the abdomen. Quite difficult to see and distinguish what is what.

I tried running it through the key for Meigenia and it didn't seem to make much sense, so I think it is not Meigenia sp and not Tachinidae.

I have looked at the possible Miltogramminae for the UK. Amobia does seem like a reasonable choice and there is only one species - A sinuata - in the UK, so that would be a relief :p

The specimen has antennae inserted well below the horizontal centre of the eyes. Closer inspection reveal that the eyes are very sparsely covered in short hairs. The claws seem to be about the same length as the 5th tarsomere, perhaps very slightly longer. There is a row of long strong bristles converging down the front of the face and a row of fine shorter and somewhat more upright hairs between these bristles and the eyes. Up near the ocellular triangle and frons the scene is more confused, with additional hairs in and around these two neat vertical rows. These hairs are more or less forward and downward pointing, and I assume meet the description for the fine hairlike proclinate orbital bristles that Amobia is supposed to have. It also matches the picture of Amobia on the Cedar Creek website, especially in the shape of the wide black laterodorsal (is that the right expression?) thoracic stripe and general shape/profile and colouration.

I have been through the other genera and it is not Macronychia because it only has 1 anterodorsal bristle on the mid tibiae; it is not Metopia because it only has a couple of bristles at the base of R4+5; it is not Miltogramma because the frontal stripe is black and nothing else about it fits for Miltogramma; it is not Oebalia because the arista is only thickened for about half its length (if that).

I also don't think it is Pterella, Senotainia or Taxigramma, but for more nebulous, harder to quantify reasons - I don't think it meets the descriptions for these, but need more experience to be sure. Senotainia, for instance, seems to have finer thoracic stripes than my specimen does.

As ever, my grateful thanks to Theo for his help, but I am beginning to think there are better ways of spending the weekend :(

Posted by Zeegers on 04-03-2007 20:24
#5

Hi Susan,

You are doing fine, do not despair !
It's not Meigenia, I can see now.
Actually, it might very well be Amobia. If so, it might be another species than signata, since the thorax has strong vittae. This is a feature of penelopei.
So, get an expert over, you might have a species new to the UK !

Theo



Posted by Susan R Walter on 05-03-2007 14:34
#6

Theo

You're an international treasure. A new to the UK! I suspect you are dangling the possibility in front of me to cheer me up, but nonetheless, it would be good to get a definitive answer on this one, so I will find out who my local Sarco expert is and get in touch with them.

I should also note that Thomas Pape's website The World of Flesh Flies was invaluable in providing descriptions for the genera in Miltogramminae. (It's listed in Web Links.)

Posted by Susan R Walter on 29-04-2007 14:15
#7

I sent this specimen to Del Smith, my county diptera recorder, and he has confirmed Amobia signata. He says 'I have no way of checking on any other Euro sp but I don't consider it worthwhile it looks typical of signata to me.'