Diptera.info :: Identification queries :: Diptera (adults)
 Ptychoptera minuta ?
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| peterbolson |
Posted on 14-08-2010 19:47
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Member Location: Cumbria, UK Posts: 276 Joined: 07.06.10 |
From my garden today. 7mm long. Wing markings not very marked, RS intermediate length, side of thorax silvery. I think it could be P.minuta, although as it's a female I believe it can't be differentiated from the rarer P.scutellaris. Could someone confirm this please as it would be a new one for me. Thanks Peter peterbolson attached the following image:  [80.65Kb] Edited by peterbolson on 14-08-2010 19:48 |
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| peterbolson |
Posted on 14-08-2010 19:48
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Member Location: Cumbria, UK Posts: 276 Joined: 07.06.10 |
another
peterbolson attached the following image:  [78.83Kb] |
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| xylo |
Posted on 16-08-2010 12:47
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 Member Location: Posts: 139 Joined: 21.08.04 |
Peter: As you already mentioned females of P. minuta-group are somewhat tricky. They can be distinguished by the length of third segment of Antennae in comparsion to the fourth + fifth segment and by distribution of wing macrotrichia around wing vein R1 (not visible in your images). Well, in the second image it seems as if antennal segment 3 is equal to 4 + 5 + 6 in length: what would make P. scutellaris. But in total I can count only 14 of normal 15 segments. P. minuta can have 3 + 4 fused. So I think it is P.minuta. so long, xylo |
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| peterbolson |
Posted on 16-08-2010 19:24
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Member Location: Cumbria, UK Posts: 276 Joined: 07.06.10 |
Thanks xylo I've had a look with the microscope & I think there are 15 segments with 3, 4 and 5 all about equal in length ( 3 slightly shorter than the other 2 ). I've tried to get a photo but it's difficult to get it all in focus at once. Peter peterbolson attached the following image:  [121.26Kb] Edited by peterbolson on 16-08-2010 19:25 |
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| xylo |
Posted on 17-08-2010 10:37
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Member Location: Posts: 139 Joined: 21.08.04 |
Hmmmm, just to clarify what I meant (cf. attachment). If there is no match, why you have ruled out P. albimana? Just realized hind metatarsi much paler than rest of tarsus. so long, xylo xylo attached the following file: pty.pdf Edited by xylo on 17-08-2010 10:38 |
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| peterbolson |
Posted on 17-08-2010 13:21
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Member Location: Cumbria, UK Posts: 276 Joined: 07.06.10 |
Hi xylo. Thanks for the attachment - I see what you mean. I'm beginning to feel out of my depth here  I thought albimana had orange on the body & that the hind metatarsus was more obviously pale than in this specimen. The key I'm following led me to minuta/scutellaris via the length & shape of RS and the silver colouring on the side of the thorax, but looking at the former again I'm not so sure - looks shorter with more of a right angle than I first thought. Do these photos help ? Peter peterbolson attached the following image:  [150.46Kb] |
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| peterbolson |
Posted on 17-08-2010 13:22
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Member Location: Cumbria, UK Posts: 276 Joined: 07.06.10 |
thorax
peterbolson attached the following image:  [144.01Kb] |
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| Roger Thomason |
Posted on 17-08-2010 14:11
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 Member Location: Mossbank,Shetland Isles. Posts: 5268 Joined: 17.07.08 |
Don't know if it is of any importance, but I have just had a similar fly posted at the same time as this one. It has been ID'd as P.albimana by xylo..http://www.dipter...ost_144356..That one has different coloured mouthparts...Don't know if this helps..or hinders  Regards Roger |
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| xylo |
Posted on 18-08-2010 11:19
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Member Location: Posts: 139 Joined: 21.08.04 |
Hi Peter & Roger! Thanks for additional pictures and suggestions. Seems as if ladies are (always) troublemaker.... ;-) I would rule out species of P. lacustris-group (P. lacustris, P. longicauda, P. paludosa) because of their shorter Rs, right angled bend confined within a black spot and thorax without silvery pubescens. Well, all Ptychoptera s. str. , those with silvery pubescens of thorax, known from Europe (according to Fauna Europaea) are: 1 Ptychoptera agnes Krzeminski & Zwick, 1993 2 Ptychoptera albimana (Fabricius, 1787) 3 Ptychoptera contaminata (Linnaeus, 1758) 4 Ptychoptera hugoi Tjeder, 1968 5 Ptychoptera minuta Tonnoir, 1919 6 Ptychoptera obscura (Peus, 1958) 7 Ptychoptera scutellaris Meigen, 1818 4 should have all palpi entirely pale 6 should have basal segment of the antenna yellow 7 antennae segment 3 very long (=4+5+6) and only apical segment of palpi dark 3 longer Rs and intense black spots 1 don't known this species; recorded only from Hungary & Slovenia so far Remaining P. albimana and P. minuta: In your image I can not spot the typical macrotricha distribution of P. albimana in first basal cell. Please recheck whether the macrotrichia distribution on wing meets with Roger's image or not (I think there is no match). Wing around vein R1 should be (nearly) free of macrotricha. Moreover, dark palpi will support P. minuta also. so long, xylo |
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| peterbolson |
Posted on 18-08-2010 13:23
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Member Location: Cumbria, UK Posts: 276 Joined: 07.06.10 |
Thanks Roger for the really helpful photos. And thanks xylo for all your fantastic help. It's much appreciated. Using my microscope I can't see any macrotrichia in the first basal cell. I've attached another photo which may help. So does this all mean that it is P.minuta ? Best wishes Peter peterbolson attached the following image:  [130.42Kb] |
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| xylo |
Posted on 19-08-2010 07:38
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Member Location: Posts: 139 Joined: 21.08.04 |
YES!!! so long, xylo |
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