Diptera.info :: Identification queries :: Diptera (adults)
 Dolichopodidae, Hydrophorus geminus (female), northern Norway
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| Geir79 |
Posted on 16-04-2012 20:39
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Member Location: Norway Posts: 689 Joined: 09.03.11 |
Is it possible to identify this one from photos? Should be genus Hydrophorus. Maybe H. rufibarbis or H. bipunctatus? Found on the surface of a pool close to the ocean in Bod�, northern Norway. Size approx. 4 mm. Geir79 attached the following image:  [129.23Kb] Edited by Geir79 on 17-04-2014 09:30 |
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| Geir79 |
Posted on 16-04-2012 20:39
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Member Location: Norway Posts: 689 Joined: 09.03.11 |
Second:
Geir79 attached the following image:  [121.18Kb] |
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| Geir79 |
Posted on 16-04-2012 20:43
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Member Location: Norway Posts: 689 Joined: 09.03.11 |
Third:
Geir79 attached the following image:  [84.77Kb] |
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| Geir79 |
Posted on 16-04-2012 20:44
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Member Location: Norway Posts: 689 Joined: 09.03.11 |
Fourth (pale hairs on front coxa)
Geir79 attached the following image:  [84.45Kb] |
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| Igor Grichanov |
Posted on 17-04-2012 08:05
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 Member Location: St.Petersburg, Russia Posts: 1821 Joined: 17.08.06 |
I'd say Hydrophorus geminus Frey (clypeus seems to be not silvery)
Igor Grichanov |
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| Geir79 |
Posted on 17-04-2012 09:51
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Member Location: Norway Posts: 689 Joined: 09.03.11 |
Is there any way to confirm H. geminus? I still have the fly. I have used d'Assis Fonseca's key, but it does not include this species. Hydrophorus geminus is not known from Norway according to Fauna Europaea...(but it's known from Sweden and Finland). |
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| Igor Grichanov |
Posted on 17-04-2012 14:11
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Member Location: St.Petersburg, Russia Posts: 1821 Joined: 17.08.06 |
4. Wings with numerous brownish-yellow-spots in anterior half; fore femur with 6-7 strong spines in basal part; 2.3-2.7........................nebulosus Fallén – Wings with 2 spots on a posterior transversal vein m-cu and on M1+2 flexure..5 5. Fore femur at apex with a small lobe, excavation and bunch of setae; IV sternite with a light spot; fore coxae with black hairs........................................6 – Fore femur at apex without an excavation and lobe ........................................7 6. Epistome mostly silvery-white, with small spot under antennae, usually two times higher than clypeus; its maximal width usually half wider than minimal width; acrostichal setae short; fore femur with short ventral hairs; proepisteron with white hairs; 3.5-5.0......................................albiceps Frey – Epistome mostly metallic-green, with weak dusting in inferior part, usually 1/3 higher than clypeus; its maximal width usually 1/4 wider than minimal width; the acrostichal setae are longer; fore femur with longer hairs; proepisteron mainly with black hairs; 4.2-5.4....................signifer Coquillett 7. The fore tibia are clearly squeezed and are strongly bent; legs with long hairs; 4.1-5.2................................................................................ rogenhoferi Mik – Fore tibia cylindrical, straight ........................................................................8 8. Epistome metallic brilliant, green; fore femur with one row of strong setae in basal part; 3.6-5.2.....................................................bipunctatus (Lehmann) – Epistome without metal shine, or if shining, then clypeus white .....................9 9. Clypeus silvery-white .................................................................................10 – Clypeus with dark-coloured dusting.............................................................12 10. Halter with a dark spot at apex, epandrial lobe at apex almost straight; 3.5- 5.4......................................................................................... borealis Loew – Halter yellow...............................................................................................11 11. Fore femur with long whitish anteroventral setae equal in length to diameter of femur; clypeus silvery-white, epistome with a metallic-green spot under antennae; 3.6-4.4 .........................................................norvegicus Ringdahl – Fore femur without long whitish anteroventral setae in apical half; face with whitish-grey tinge; 2.9-3.9...........................................rufibarbis Gerstäcker 12. Leg without long hairs; halter dark; 3.8-4.4..............................geminus Frey – Midtibia with long hairs exceeding in length diameter of tibia, halter usually light with dark knob; 3.2-4.8...................................................... pilipes Frey Grichanov, I.Ya., 2006. A checklist and keys to North European genera and species of Dolichopodidae (Diptera). - VIZR RAAS (Plant Protection News, Supplement) 2006: 1-120. http://www.dipter...p?cat_id=8 Igor Grichanov |
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| Geir79 |
Posted on 17-04-2012 17:22
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Member Location: Norway Posts: 689 Joined: 09.03.11 |
Thank you for the link to the key to Dolichopodidae. It seems more like Hydrophorus pilipes? The halters are light with a dark knob? Middle tibia have long hairs (don't know if they're long enough?). Length from measure with USB microscope is 4,50 mm. Geir79 attached the following image:  [153.01Kb] Edited by Geir79 on 17-04-2012 17:26 |
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| Geir79 |
Posted on 17-04-2012 17:23
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Member Location: Norway Posts: 689 Joined: 09.03.11 |
Close up of middle tibia:
Geir79 attached the following image:  [105.44Kb] |
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| Geir79 |
Posted on 17-04-2012 17:24
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Member Location: Norway Posts: 689 Joined: 09.03.11 |
A last photo showing side of body better:
Geir79 attached the following image:  [170.29Kb] Edited by Geir79 on 17-04-2012 17:25 |
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| Stefan Naglis |
Posted on 17-04-2012 17:53
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Member Location: Switzerland Posts: 738 Joined: 27.12.08 |
I can see only 2 setae on the scutellum. If this is the case than it is Hydrophorus oceanus Macquart. |
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| Geir79 |
Posted on 17-04-2012 18:15
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Member Location: Norway Posts: 689 Joined: 09.03.11 |
It has 4 setae on the scutellum? I'm not very experienced with this though  Photo of scutellum, hope this helps with determining. Geir79 attached the following image:  [164.21Kb] |
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| mossnisse |
Posted on 17-04-2012 19:22
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 Member Location: Sweden, Umeå Posts: 442 Joined: 19.01.12 |
Grichanov has also this key online http://www.fortunecity.com/greenfield/porton/875/SwedenHydrophorus.htm I have found H. borealis in northern Sweden and another species without spots on the wings i can't identify and a smaller one up in the mountains. |
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| Geir79 |
Posted on 17-04-2012 19:53
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Member Location: Norway Posts: 689 Joined: 09.03.11 |
Thank you. Is it a female? I've some problems figuring out which sex it is....(normally not a problem, but in some genera I think it's not so obvious). It could be H. borealis then? I don't have much to compare with, think it's difficult only using keys to determine insects. Attaching a photo of sternites... Geir79 attached the following image:  [182.79Kb] |
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| Stefan Naglis |
Posted on 17-04-2012 20:06
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Member Location: Switzerland Posts: 738 Joined: 27.12.08 |
I agree with Igor: Hydrophorus geminus Frey female |
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| Geir79 |
Posted on 17-04-2012 20:15
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Member Location: Norway Posts: 689 Joined: 09.03.11 |
Yes, thank you! I agree too after going through the key again. I keyed it as a male the first time. It is a female, right?? Then it ends up as geminus (I've also found a H. borealis female and male at the same location). Edited by Geir79 on 17-04-2014 09:31 |
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