Posted by blowave on 22-09-2011 20:38
#8
Sundew wrote:
According to the
Eristalis key (
http://web.archiv...html#item8),
E. abusivus has a short-haired arista and is thus out of the question. I could live with
E. arbustorum...
The link doesn't give the key but I have those anyway. I bought the book too, the first couplet which leads to
abusiva states hairs shorter than twice the diameter of arista base or bare. The other option states hairs much longer than twice the diameter of arista. I'm not sure which this fits into, the hairs do appear to be longer but I wouldn't say much longer and photos don't always show the reality.
I have looked at other keys but still can't decide! If I follow the Syrph the Net keys using the option of arista hairs no more than 2x diameter it leads to abusiva, some alternative options en route are not in the UK or are obviously not appropriate. The other option is arista hairs more than 3x diameter.