Posted by John Bratton on 14-12-2006 20:09
#1
I think I have some specimens of Sphegina sibirica from Breconshire, Wales, but there seems to be some inconsistency in the literature. Stubbs & Falk 2nd edition says the chitinous plate behind the hind coxae is incomplete, and the face is yellowish. But van Veen's 2004 book says the face is black, and if I have interpreted it correctly his fig. 733 shows the chitinous plate has no gap in it. My specimens fit van Veen's version. Is it just a variable species? Any comments, please?
John Bratton, Menai Bridge
Posted by Kahis on 14-12-2006 20:48
#2
Forget about the colour characters; S. sibirica varies from all-yellow to almost-all black. The 1st sternite is a good character and van Veen illustrates it well on page 207: All other Sphegina species has a well-developed chitinous plate on the ventral side of the base of abdomen (the vaguely 2-lobel thing in fig. 732). S. sibirica has no such plate as shown in fig. 733.
Posted by John Bratton on 16-12-2006 12:00
#3
Thanks very much, I am happy I have the right name for them now.
John