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 Syrphus ribesii?
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| Nikita Vikhrev |
Posted on 13-06-2006 13:48
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 Member Location: Posts: 9193 Joined: 24.05.05 |
Moscow region, 10 june, 10-11mm.
Nikita Vikhrev - Zool Museum of Moscow University |
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| Susan R Walter |
Posted on 13-06-2006 13:57
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 Member Location: Posts: 1794 Joined: 14.01.06 |
Nikita - I think (from memory) that it is impossible to distinguish S ribesii and S vitripennis females. Definitely Syrphus sp, but I'd have to go to my books to get any further.
Susan |
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| Nikita Vikhrev |
Posted on 13-06-2006 23:22
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Member Location: Posts: 9193 Joined: 24.05.05 |
Thank you Susan. In my key S. vitripennis female - f3 - black 2/3 from base, S. ribesii female - f3 - all yellow. I can't understand whether black ring on f3 on photo is result of wing shadow of flash light or it is realy black. Could you? Nikita Vikhrev - Zool Museum of Moscow University |
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| Nikita Vikhrev |
Posted on 13-06-2006 23:46
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Member Location: Posts: 9193 Joined: 24.05.05 |
Susan, I need medical treatment to stop gaps in my memory, - fly is collected! f3 - clearly black in base 2/3. So, according my key (the old one as you remember) it is Syrphus vitripennis. Thank you again. Nikita Vikhrev - Zool Museum of Moscow University |
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| Susan R Walter |
Posted on 14-06-2006 13:05
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Member Location: Posts: 1794 Joined: 14.01.06 |
Nikita The black on the hind femora was the character I was thinking of, but knew you could only distinguish one of the sexes this way and the other is indistinguishable. Must be males you can't distinguish. I'll try to check my key when I have time (or someone like Gerard will enlighten us). Susan |
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| Menno Reemer |
Posted on 14-06-2006 14:44
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Member Location: Posts: 343 Joined: 10.06.04 |
This is a female S. torvus: the hairs on the eyes are short (as usual in females), but clearly visible. In this species the female - as in S. vitripennis - also has partly black hind femora. |
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| Nikita Vikhrev |
Posted on 14-06-2006 15:57
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Member Location: Posts: 9193 Joined: 24.05.05 |
Thank you Menno.
Nikita Vikhrev - Zool Museum of Moscow University |
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| Robert Nash |
Posted on 14-06-2006 16:58
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Member Location: Posts: 288 Joined: 11.11.05 |
It's torvus ok but the term short (in short hairs) raises a question. How short is short and under which microscope or magnification? A fundamental problem of working with words not pictures And how about setulae -sort setae? Calling a sore back lumbago does not solve the problem. |
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| Menno Reemer |
Posted on 15-06-2006 08:26
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Member Location: Posts: 343 Joined: 10.06.04 |
In this case it doesn't really matter, because S. torvus is the only one of these three species with hairy eyes. The narrowness and pale fasciae on the abdomen also suggest it's torvus. How narrow is narrow? How pale is pale? This is a matter of experience. In preserved specimens you could also check the microtrichia on the wing: entirely covered in S. torvus & S. ribesii, while large parts are bare in S. vitripennis. |
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| pierred |
Posted on 15-06-2006 19:57
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 Member Location: Posts: 1413 Joined: 21.04.05 |
Hi, Thanks for all this, because one would have a hard work to express it so clearly within a key. Pierre Duhem |
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but don't see the image in the post.
