Thread subject: Diptera.info :: Cecidomyiidae UK - differences between 2 sp.

Posted by MrsL on 24-09-2014 13:31
#1

Hi,

Hopefully I'm doing this right - I don't use forums often!

I'm ID'ing a lot of Cecidomyiidae taken from habitat surrounding oil seed rape. I am getting a lot that are either Dasineura brassicae or Gephyraulus raphanistri but cannot distinguish between the 2. My key (Kirk 1992) uses colour as the main physical distinguishing factor and tihs is very difficult to make out.

I was wondering if anyone was aware of any other distinguishing characters that I could use?

I don't know whether they lay eggs in pods or flowers as they were collected via suction sample...

Any help would be greatly appreciated,
Thanks!

L

Posted by John Carr on 24-09-2014 14:48
#2

Distinguishing genera of Cecodomyiinae is a very ambitious project.

Quoting Gagné (2006):

"Except for the female postabdomen, the included species [of Gephyraulus] could pass for Dasineura...

"In the key to genera of Neotropical Lasiopteridi in Gagné 1994, Gephyraulus will run to Dasineura. The characters of Gephyraulus that separate it from Dasineura are: the modified female postabdomen, including the strongly sclerotized 7th and 8th terga and the bilaterally flattened ovipositor with its stiff, glabrous, fused cerci; the medially angled parameres and the foreshortened gonostyli of the male genitalia, which presumably serve to accommodate the shape of the ovipositor; and the lengthier posterior end of the female pupa conforming to the robust and stiff adult postabdomen inside."

Posted by MrsL on 24-09-2014 15:09
#3

That's great, many thanks for the speedy response! I'll take a look and see if I can spot the difference. Have a great day!