Diptera.info :: Identification queries :: Diptera (adults)
 Helophilus continuus/affinis/pendulus?
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| Jens Nielsen |
Posted on 23-07-2006 15:09
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Member Location: Posts: 21 Joined: 09.07.06 |
I've made a few photo's of this hoverfly which is, as far as I've been able to determine from Collin's general insect field guide and some internet sources a Helophilus species (female), and I think either H. continuus/affinis/pendulus, probably the last one. Can anyone positively identify this species? The specimen was found in The Hague, The Netherlands on 9 August 2006. When I've positively identified it, the picture will be put on the Wikipedia, so to avoid any perpetuation of a mistake, it's essential that it is not labelled with a wrong species name. Thanks in advance, Jens Nielsen ex-biologist and Wikipedian Edited by Jens Nielsen on 23-07-2006 15:19 |
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| Jens Nielsen |
Posted on 23-07-2006 15:11
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Member Location: Posts: 21 Joined: 09.07.06 |
top view:
Jens Nielsen attached the following image:  [88.39Kb] Edited by Jens Nielsen on 23-07-2006 15:16 |
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| Jens Nielsen |
Posted on 23-07-2006 15:12
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Member Location: Posts: 21 Joined: 09.07.06 |
I'm having some problems posting this image, please bear with me if something fails here.
Jens Nielsen attached the following image:  [7.97Kb] Edited by Jens Nielsen on 23-07-2006 15:14 |
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| Jens Nielsen |
Posted on 23-07-2006 15:15
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Member Location: Posts: 21 Joined: 09.07.06 |
here third picture showing head and antennae more clearly.
Jens Nielsen attached the following image:  [28.33Kb] |
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| Tony Irwin |
Posted on 23-07-2006 15:57
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 Member Location: Norwich, England Posts: 7342 Joined: 19.11.04 |
Hi Jens A fine female pendulus. No doubt. Tony ---------- Tony Irwin |
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| Xespok |
Posted on 23-07-2006 20:03
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 Member Location: Debrecen, Hungary Posts: 5551 Joined: 02.03.05 |
The separation of the species within the genus, especially between pendulus and triittatus also puzzled me. After looking through many IDed images, it appears to me that the best feature is the top of the second abdominal segment. The two small spots in the middle are more pronounced and often have a different colour in pendulus. What other features separate the two species? Am I right that this is a reliable feature? H. pendulus is much scarcer around here in Hungary, than trivittatus. I have not seen any other species in that genus. Edited by Xespok on 23-07-2006 20:06 |
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| Kahis |
Posted on 23-07-2006 20:24
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 Member Location: Helsinki, Finland Posts: 1999 Joined: 02.09.04 |
There's a very easy way to tell H. trivittatus apart from all other Helophilus: it has a all-yellow face while the other species have a black vertical stripe. This black band is well visible in your 2nd small image above. H. trivittatus is a large species and the pale areas on the 4th tergite (3rd large plate on top of abdomen) usually form a band. Other species have elongated spots almost touching each other. The spots on 4th tergite are H. hybridus board and darker than pale areas on previous tergites. H. pendulus has narrower, sausage-shaped spots on 4th tergite. See http://www.veluwe...hilus.html for photos of these species. This leaves us with H. affinis to describe. It is not rare in Finland, but I understand it is nor often seen in Central Europe. The females of this species are close to H. pendulus, the males closer to H. hybridus. Kahis |
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