Thread subject: Diptera.info :: Muscidae: Helina pertusa

Posted by Stephen R on 26-05-2011 23:45
#1

c. 8mm, Clitheroe UK, 22 May 2011.

From this and other images I arrived at Helina pertusa. Does this look right? Should I bring more pictures? (No specimen.)

Edited by Stephen R on 29-05-2011 21:40

Posted by Stephane Lebrun on 27-05-2011 17:15
#2

It could be. How many katepisternal, how long is the pre-alar ? I only catch Helina lasiophthalma at the moment which could also be.

Posted by Stephen R on 27-05-2011 18:42
#3

This gives the best view of these features. I think katepisternals are 2+2, and the pre-alar looks weak.

Posted by Stephane Lebrun on 27-05-2011 19:14
#4

Seems consistent with H. pertusa, but the best way to get a certitude is to catch a specimen.

Posted by Stephen R on 27-05-2011 21:10
#5

I'll see what I can do. :) Other things which seemed to confirm H. pertusa were the the single ad on t3 and the strongly infuscated crossveins. I can't find any sign of eye hairs. and the arista is very short-haired:

Edited by Stephen R on 27-05-2011 21:12

Posted by Stephen R on 27-05-2011 22:01
#6

Incidentally, when the keys speak of 'katepisternals 1 + 2', does the first number always refer to the anterior position, or the opposite, or is there no convention?

Posted by Stephane Lebrun on 27-05-2011 22:06
#7

Stephen R wrote:
Incidentally, when the keys speak of 'katepisternals 1 + 2', does the first number always refer to the anterior position?


Yes, one anterior and two posterior.

Posted by Stephen R on 27-05-2011 22:37
#8

Thanks. This is the view from the other side - again 2 anterior setae, the lower one weaker.

Posted by Stephen R on 27-05-2011 22:54
#9

and this is the 'money shot' for the pre-alar!

Posted by Stephane Lebrun on 28-05-2011 10:18
#10

The pra is not so weak, and the arista seems almost bare. That trouble me. Catch one if you have the opportunity.

Posted by Stephen R on 28-05-2011 10:23
#11

I'll go out and look now!

Posted by Stephen R on 28-05-2011 12:25
#12

Well, I got one, and it's a male with bare eyes - I only had to search 20 damp mossy tree trunks B). Photos to follow.

(I also got a Phaonia pallida male and a Sciapus platypterus - not a bad habitat to look at on a dull day.)

Here's the male specimen. It does key out as H. pertusa.

Edited by Stephen R on 28-05-2011 18:17

Posted by Stephen R on 28-05-2011 18:11
#13

Four rows of pre ac.

Edited by Stephen R on 28-05-2011 18:16

Posted by Stephen R on 28-05-2011 18:12
#14

3

Posted by Stephen R on 28-05-2011 18:14
#15

4

Posted by Stephane Lebrun on 29-05-2011 20:11
#16

Great. The dense hairiness beneath the hind femur seems here too...

Posted by Stephen R on 29-05-2011 21:39
#17

Yes, it's very clear on the specimen. Many thanks for your patience and rigour! Would you like the specimen?