The Society for the study of flies (Diptera)

colinleb · 2012-01-29 19:36:49

I am stuck at the first couplet of Stubbs & Drake key for Machimus. The femora of this specimen is certainly not “entirely black”, but the brownish-orange marks don’t seem to be “clearly defined” either. Combination of other characteristics indicates atricapillus.

Uploaded Images

falky · 2012-01-29 23:54:52

Colin,

Looks like atricapillus to me, and certainly not rusticus or arthriticus, so concentrate on separation from cingulatus,

Cheers,

Falky

malcolmsmart · 2012-01-30 13:20:52

The femora are indeed quite dark on your specimen but not completely black. This female is definitely either M.atricapillus of M. cingulatus. I discuss separation of these 2 species (With detailed photographs)in my paper in DD vol 12 No.1 pp 61-68 (2005). Unfortunately Your pictures do not clearly show the key characters. The first picture seems to show strong bristles under sternites 2 & 3 which would be indicative of M. cingulatus but the second picture appears to show the front tibia to lack an apparent dark mark across its middle which should be present in front view of M. cingulatus.

If you can take pictures showing the full front view of the front tibiae and a true side view of the showing the profile of the hairs/bristles under the tergites not obscured by the hind femur (at the highest possible magnification), we should be able to confirm the identification. I attach extracts from the illustrations in my paper showing the difference in the tibiae markings and the sternite bristles.

I hope that this helps.
Malcolm

Uploaded Images

Mark · 2012-01-30 17:20:35

Malcolm the first picture is so helpful!

printed and stuffed into my Stubbs & Drake.

colinleb · 2012-02-01 01:09:35

Thanks Falky

Thanks Malcolm – as a latecomer to Diptera my DDs start from 2008 with a few odd prior issues. I’ll ask Mick Parker if 2005 is still available.
I attach photos of the front tibia and lateral abdominal view of this specimen. There is a strong black antero-dorsal line along the tibia but it does not appear to broaden. The ventral abdominal hairs all appear similar to one another.

Uploaded Images

Mick · 2012-02-01 02:20:16

colinleb wrote:
Thanks Falky

Thanks Malcolm – as a latecomer to Diptera my DDs start from 2008 with a few odd prior issues. I’ll ask Mick Parker if 2005 is still available.
I attach photos of the front tibia and lateral abdominal view of this specimen. There is a strong black antero-dorsal line along the tibia but it does not appear to broaden. The ventral abdominal hairs all appear similar to one another.

Hi Colin,
Yes! Volume 12 parts 1 & 2 is still available, £5 ( per copy ) from me at my address,
Cheers,
Mick

Last edited by Mick (2012-02-01 02:22:05)

malcolmsmart · 2012-02-01 14:30:12

Hi Colin,
Your pictures show that your specimen is M. atricapillus. As you note the stripe on the front tibiae does not expand across the middle of the anterior face to give the appearence of a central ring. The longer bristles on the sternites 3 & 4 are as fine as those on segment 2 - they do not become noticably coarser from segment 2 to segment 4 as in M. cingulatus. I appreciate that this latter character is hard to appreciate and difficult to photograph, but it would become obvious if you had specimens of both species together for comparison. My 2005 paper discusses it at some length.
Malcolm

The Society for the study of flies (Diptera)

#1 2012-01-29 19:36:49

ID help needed with Machimus

#2 2012-01-29 23:54:52

Re: ID help needed with Machimus

#3 2012-01-30 13:20:52

Re: ID help needed with Machimus

#4 2012-01-30 17:20:35

Re: ID help needed with Machimus

#5 2012-02-01 01:09:35

Re: ID help needed with Machimus

#6 2012-02-01 02:20:16

Re: ID help needed with Machimus

colinleb wrote:

#7 2012-02-01 14:30:12

Re: ID help needed with Machimus

Board footer