Thread subject: Diptera.info :: Eristalis with 'deep' head?
Posted by Jason G on 01-11-2010 00:48
#1
Evening all,
I collected this fly in May or so, in London. Now, I've tried keying it out using van Veen's key (
I'll get S&F once I have a few more RES keys while they're in stock), and got to coup. 9 - http://web.archive.org/web/20070423163827/http://home.hccnet.nl/mp.van.veen/KEYS/Eristalis/eristkey.html#item9
Now, under the microscope the tarsi are dark brown with few pale hairs except for the basal half of the first tarsus which is pale. I think this steers it away from
pertinax, and away from
arbustorum since the top-half of tibia2 is pale.
Now, the head in profile appears quite deep (
to me!), but
jugorum isn't on the British list. If it isn't this one, then following it on you come to
lineata - except there are no black hairs at all on T3-4 - distal or otherwise.
So... any thoughts on the basis of these images? I don't know how accurate the key is compared to Mark's original work and I will try with the UK key when I get it - but can get additional photographs if they may help.
Thanks for reading.
Take care,
Jason
Edited by Jason G on 01-11-2010 02:23
Posted by Jason G on 01-11-2010 00:49
#2
Lateral... note the apparently dark tarsi and the way the lower part of the head is quite 'inflamed' - it's deeper than my others -
E. tenax,
arbustorum and
intricarius.
Edited by Jason G on 01-11-2010 00:54
Posted by Jason G on 01-11-2010 00:51
#3
Head...
I suspect it IS
pertinax, it just looks quite unusual in my limited experience.
Edited by Jason G on 01-11-2010 01:02
Posted by Auratus on 01-11-2010 08:04
#4
It seems the pterostigma is very small. Also an important feature ;)
Posted by Jason G on 01-11-2010 16:32
#5
New views taken today - the Pterostigma...
Posted by Jason G on 01-11-2010 16:33
#6
Side-view of the head...
Posted by Jason G on 01-11-2010 16:34
#7
...and the front tarsi - brownish, not yellow in my opinion.
Posted by Quaedfliegh on 01-11-2010 17:29
#8
I think Jan is referring to a species with small pterostigma; E. nemorum. With Dutch key that is the conclusion.
Posted by Jason G on 01-11-2010 19:37
#9
Sorry Jan! I didn't see your reply. Apologies! That looks great - isn't that now
Eristalis interrupta?
Thanks for highlighting that for me + providing the name, Reinoud!
I'll now back-track through the couplets, and find where I went wrong.
Thanks again! :)
Posted by Andre on 03-11-2010 20:48
#10
'Deep head'....? LOL :P