Diptera.info :: Family forums :: Syrphidae
 Eristalis with 'deep' head?
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| Jason G |
Posted on 01-11-2010 00:48
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 Member Location: London UK Posts: 136 Joined: 22.12.08 |
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 Jason G attached the following image:  [113.36Kb] Edited by Jason G on 01-11-2010 02:23 London's Insects http://londoninve...hostia.com |
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| Jason G |
Posted on 01-11-2010 00:49
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Member Location: London UK Posts: 136 Joined: 22.12.08 |
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.
Jason G attached the following image:  [53.43Kb] Edited by Jason G on 01-11-2010 00:54 London's Insects http://londoninve...hostia.com |
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| Jason G |
Posted on 01-11-2010 00:51
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Member Location: London UK Posts: 136 Joined: 22.12.08 |
Head... I suspect it IS pertinax, it just looks quite unusual in my limited experience. Jason G attached the following image:  [57.73Kb] Edited by Jason G on 01-11-2010 01:02 London's Insects http://londoninve...hostia.com |
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| Auratus |
Posted on 01-11-2010 08:04
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Member Location: Edam - Netherlands Posts: 410 Joined: 24.05.10 |
It seems the pterostigma is very small. Also an important feature 
Greetings, Jan |
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| Jason G |
Posted on 01-11-2010 16:32
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Member Location: London UK Posts: 136 Joined: 22.12.08 |
New views taken today - the Pterostigma...
Jason G attached the following image:  [53.06Kb] London's Insects http://londoninve...hostia.com |
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| Jason G |
Posted on 01-11-2010 16:33
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Member Location: London UK Posts: 136 Joined: 22.12.08 |
Side-view of the head...
Jason G attached the following image:  [80.65Kb] London's Insects http://londoninve...hostia.com |
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| Jason G |
Posted on 01-11-2010 16:34
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Member Location: London UK Posts: 136 Joined: 22.12.08 |
...and the front tarsi - brownish, not yellow in my opinion.
Jason G attached the following image:  [63.74Kb] London's Insects http://londoninve...hostia.com |
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| Quaedfliegh |
Posted on 01-11-2010 17:29
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 Member Location: Tilburg Netherlands Posts: 2219 Joined: 18.05.10 |
I think Jan is referring to a species with small pterostigma; E. nemorum. With Dutch key that is the conclusion.
Greetings, Reinoud Field guide to the robber flies of the Netherlands and Belgium: https://www.jeugdbondsuitgeverij.nl/product/field-guide-to-the-robberflies-of-the-netherlands-and-belgium/ https://www.nev.nl/diptera/ |
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| Jason G |
Posted on 01-11-2010 19:37
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Member Location: London UK Posts: 136 Joined: 22.12.08 |
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! 
London's Insects http://londoninve...hostia.com |
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| Andre |
Posted on 03-11-2010 20:48
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 Member Location: Tilburg, the Netherlands Posts: 2111 Joined: 18.07.04 |
'Deep head'....? LOL  |
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