Posted by Nosferatumyia on 28-04-2009 19:34
#5
Dear Kurt, no external characters work with certainty for these two species. Inthe females, they clearly differ by the length of the ovipositor, in males, by the phallus structure. I'd say its wing pattern is more common for difficilis, but only 30-40% specimens can be discriminated by the wing pattern along.