Diptera.info :: Identification queries :: Diptera (adults)
 Ocelli Lit Up Blue
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| Stephen |
Posted on 24-10-2006 14:02
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 Member Location: West Virginia USA Posts: 1322 Joined: 12.04.05 |
Looks similar to a Hydrophorus sp. I photographed. Is that what this fly is? What stout leg spines! The eyes have a lot of white hair on them. Another interesting thing is that the ocelli lit up blue, in all the pictures I took of this fly (they are flash pictures). On the shore of a pond, in the mountains, West Virginia, USA, on 16 August 2006. Length 5 mm. Stephen attached the following image:  [103.37Kb] Edited by Stephen on 25-10-2006 16:43 --Stephen Stephen Cresswell www.americaninsects.net |
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| Stephen |
Posted on 25-10-2006 16:45
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Member Location: West Virginia USA Posts: 1322 Joined: 12.04.05 |
Rats, no comments. Surely a Doli, anyhow, with the long legs and the leg spines and the pond shore habitat? Those spines seem more extreme than most I've seen on a Doli. --Stephen Stephen Cresswell www.americaninsects.net |
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| Tony Irwin |
Posted on 25-10-2006 18:19
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 Member Location: Norwich, England Posts: 7306 Joined: 19.11.04 |
I'm no doli expert, but I'd agree with your family diagnosis. As to genus, I expect a US doli person may recognise those particularly spiky legs, but they're not familiar to me.
Tony ---------- Tony Irwin |
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| Kahis |
Posted on 25-10-2006 18:33
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 Member Location: Helsinki, Finland Posts: 1999 Joined: 02.09.04 |
First thoughs say Tachytrechus, but they are notoriously unreliable. None of the critical characters are visible and I'm not al all familiar with the NA fauna. The metallic blue spots are not ocelli but sides of the ocellar triangle. The paired posterior ocelli can be seen between the blue reflections. Kahis |
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| Nikita Vikhrev |
Posted on 25-10-2006 19:41
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 Member Location: Moscow, Russia Posts: 9475 Joined: 24.05.05 |
I think it is blue reflection of blue sky by shining surface.
Nikita Vikhrev - Zool Museum of Moscow University |
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| Paul Beuk |
Posted on 25-10-2006 20:04
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 Super Administrator Location: Netherlands Posts: 19403 Joined: 11.05.04 |
No, the blue is really part of the body colour, not of the sky because you also see it on specimens in collections when no daylight is visible. 
Paul - - - - Paul Beuk on https://diptera.info |
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| Stephen |
Posted on 25-10-2006 23:14
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Member Location: West Virginia USA Posts: 1322 Joined: 12.04.05 |
Just for fun I have enlarged the area around the ocelli and the blue spots. I presume without the flash these would not have been so brilliant. Nice silver spots too! I checked to see if I might have a view of this fly from the side but I don't. Next summer I will crawl on my belly through the mud and get a lateral view, which might help with the ID. Maybe a view of the "face" too. Thanks Tony, Nikita, Kahis, Paul! Stephen attached the following image:  [48.24Kb] Edited by Stephen on 25-10-2006 23:16 --Stephen Stephen Cresswell www.americaninsects.net |
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| Igor Grichanov |
Posted on 26-10-2006 09:59
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 Member Location: St.Petersburg, Russia Posts: 1783 Joined: 17.08.06 |
The vertex is shining blue between eyes and ocelli. The fly looks closer to Paraclius than to Tachytrechus: high hind femur with 1 subapical seta, broad face, middle vein close to wing apex. But some species are still travelling from one genus to another (see Nearctic Catalog, 2004). Good luck, Igor. |
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| Igor Grichanov |
Posted on 26-10-2006 11:23
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Member Location: St.Petersburg, Russia Posts: 1783 Joined: 17.08.06 |
Many Dolichopodinae (subfamily) are very spinose. See Dolichopus trivialis. Igor. Igor Grichanov attached the following image:  [24.61Kb] |
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| Stephen |
Posted on 28-10-2006 11:12
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Member Location: West Virginia USA Posts: 1322 Joined: 12.04.05 |
Igor, Thanks for your help with this fly!
--Stephen Stephen Cresswell www.americaninsects.net |
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