Diptera.info :: Identification queries :: Diptera (adults)
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 Muscidae: Coenosia albicornis
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| Stephen R |
Posted on 24-01-2010 18:03
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 Member Location: Clitheroe Lancashire UK Posts: 2396 Joined: 12.06.09 |
I posted these photos in October, when I found this moribund Coenosia, but later deleted the post after there were no takers. Now I am the proud possessor of an antique Nikon stereo microscope from Ebay and a copy of Muscidae of Central Europe, so I thought I'd have a go at my only specimen. Unfortunately the key led me to a species (C. emiliae) we don't have in Britain. Is it probable that this fly is one the book doesn't cover, or have I gone horribly wrong somewhere? The characters are checked were: No approximated av +ad on t3 no dilated 5th tarsomere no approximated d+pd on t3 long lower squama female no spine-like tip to flagellomere proepisternum with 2 setae pd on t3 no ad on t1 femora not entirely yellow Shall I give up and wait for something easier to fly along? Stephen R attached the following image:  [97.99Kb] Edited by Stephen R on 16-07-2010 16:07 |
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| Stephen R |
Posted on 24-01-2010 18:04
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Member Location: Clitheroe Lancashire UK Posts: 2396 Joined: 12.06.09 |
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Stephen R attached the following image:  [89.29Kb] |
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| jorgemotalmeida |
Posted on 24-01-2010 19:06
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 Member Location: Viseu - PORTUGAL Posts: 9296 Joined: 05.06.06 |
Stephen R wrote: Now I am the proud possessor of an antique Nikon stereo microscope from Ebay ? How much did the Nikon stereo microscope cost? |
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| Stephen R |
Posted on 24-01-2010 19:08
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Member Location: Clitheroe Lancashire UK Posts: 2396 Joined: 12.06.09 |
I paid 99 GBP + about 10 pounds postage. Optically it is very good. This is the one: http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=180454931065& Edited by Stephen R on 24-01-2010 19:15 |
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| javanerkelens |
Posted on 24-01-2010 20:28
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 Member Location: Netherlands Posts: 2962 Joined: 18.10.07 |
1: what is the sice of the fly 2: I can't see it proper, but are you sure the hind tibia hasn't strong preapical dorsal and posterodorsal seta close to another? 3: and a dorsal view of the thorax would also be nice (acrostichals etc.) Joke |
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| Stephen R |
Posted on 25-01-2010 21:50
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Member Location: Clitheroe Lancashire UK Posts: 2396 Joined: 12.06.09 |
Hi Joke, The size is 4.5mm. I think my mistake was to say there was a pd on T3 - I think the one I was looking at was truly dorsal. Assuming that, I get through eventually to C. albicornis, provided that you count the white line down the frons as part of the frontal triangle. Here are pictures of the hind tibiae and the thorax. What do you think? Stephen R attached the following image:  [86.4Kb] |
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| Stephen R |
Posted on 25-01-2010 21:51
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Member Location: Clitheroe Lancashire UK Posts: 2396 Joined: 12.06.09 |
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Stephen R attached the following image:  [88Kb] |
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| Stephen R |
Posted on 25-01-2010 21:53
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Member Location: Clitheroe Lancashire UK Posts: 2396 Joined: 12.06.09 |
The acrostichals are in 2 rows:
Stephen R attached the following image:  [125.48Kb] |
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| Stephen R |
Posted on 25-01-2010 21:58
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Member Location: Clitheroe Lancashire UK Posts: 2396 Joined: 12.06.09 |
This is one of the thorax from when I first found it, and it shows the frontal triangle. Since the fly came out of the alcohol I keep losing bits - I'll have to get better at handling specimens!
Stephen R attached the following image:  [119.05Kb] Edited by Stephen R on 25-01-2010 22:27 |
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| javanerkelens |
Posted on 25-01-2010 23:35
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Member Location: Netherlands Posts: 2962 Joined: 18.10.07 |
When i check everythink with what i can see, ....i also come to C.emiliae Lukasheva 1986 (only found yet in Germany, Czech Republic and Slovakia) Fore femur infuscated, dorso-apical markings on hindtibia (can see clear the dorsal side of midfemur) t2 with ad and t3 with 1av+1ad+1pd The only mistake maybe made , can be the hairs on proepisternum.....then it would be an C.rufipalpis..? (female not always have beginning of abdomen yellow) And C. albicornis has no pd on t3! Maybe Nikita or Stephane could say more .... Joke  |
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| Stephen R |
Posted on 26-01-2010 11:23
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Member Location: Clitheroe Lancashire UK Posts: 2396 Joined: 12.06.09 |
Thank you Joke. I am sure about the proepisternum - two bristles, the anterior one shorter. But I am not really clear about the orientation of bristles on the tibia, and whether the 'pd' on t3 should be counted instead as dorsal. It seems to be in the plane of flexion of the leg joints. How is 'dorsal' defined? Stephen. |
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| javanerkelens |
Posted on 26-01-2010 15:30
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Member Location: Netherlands Posts: 2962 Joined: 18.10.07 |
In the beginning i had the most problems, how to place the leg in the right position. I made from the anterior dorsal a posterior dorsal and from the posterior dorsal a posterior ventral..etc.  The hindtibia has for 90 % only av+ad+pd+pv setae and mostly no anterior and posterior seta (sometimes the pv setae are more in a posterior position, but mostly these setae gives not the most problems) I think on your species the seta is a pd seta and no posterior seta.. I made a drawing of the setae (maybe helpful) and a example on a fly Joke
javanerkelens attached the following image:  [75.42Kb] Edited by javanerkelens on 26-01-2010 18:59 |
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| javanerkelens |
Posted on 26-01-2010 15:32
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Member Location: Netherlands Posts: 2962 Joined: 18.10.07 |
and another example (on the foreleg mostly the setae are anterior and posterior and not av+ad+pd+pv !!) javanerkelens attached the following image:  [100.85Kb] |
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| jorgemotalmeida |
Posted on 26-01-2010 16:54
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Member Location: Viseu - PORTUGAL Posts: 9296 Joined: 05.06.06 |
suggestions: the first sketch at the left put below: LATERAL VIEW of the leg. The middle: SEEN AS ABOVE, as we cut the leg transversally, being the ventral.. the underside of the leg. (exempli gratia, ventral seta/bristle: the insertion of the ventral bristle is located in the underside of the leg (considering the frontal view of the last photo) . So we almost (see below the text) cannot see in this last photo the insertion of ventral setae with the most proximal legs (foreground) to us, the distal ones sometimes show them but not easy to see! However, we can see the point of insertion of ventral bristles IF the leg is twisted like it happens in the hind tibia where we can see av with its insertion point - I'm considering the fly as always being transverse with us.) The right sketch (above all of them) I would suggest to put below the legend SEEN AS ABOVE , but this time, as we had our fly with the biggest length transversally to us. This view is perfectly showed in the last photo. (caution: the hind tibia is gently twisted in this view. That's why we see many ad) Edited by jorgemotalmeida on 26-01-2010 17:15 |
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| Stephen R |
Posted on 26-01-2010 18:52
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Member Location: Clitheroe Lancashire UK Posts: 2396 Joined: 12.06.09 |
Joke and Jorge, many thanks for your illustrations and explanations, which are very clear. From what you say there should be a 90 degree difference between an av and a pd, and this looks right for the fly in your picture - there are no bristles on the line going down from the very tip of the knee; but in my fly the bristle seems only 45 degrees round from the ad bristles. Does this not make it dorsal? |
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| javanerkelens |
Posted on 26-01-2010 19:06
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Member Location: Netherlands Posts: 2962 Joined: 18.10.07 |
Always very difficult to explane, because the legs are never clear in dorsal, anterior, etc. view (on photos) Maybe everyone is already tired of all the drawings , but a last one to give it a try.....From what you say there should be a 90 degree difference between an av and a pd Not always, because you can see there is a relative wide area where a pd or ad can be in the posteriordorsal and anterior dorsal area. So if the ad almost is standing near the "dorsal line" and the pd is also more near the "dorsal line"....the differents can be less 90 degree ! Joke (Jorge, i made some changes in my first drawing..  )
javanerkelens attached the following image:  [78.75Kb] Edited by javanerkelens on 26-01-2010 19:23 |
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| Stephen R |
Posted on 26-01-2010 23:12
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Member Location: Clitheroe Lancashire UK Posts: 2396 Joined: 12.06.09 |
Are you saying that anything in the 90 degree sector between the dorsal and the posterior directions is called posterdorsal, and that you only refer to a seta as dorsal if it is exactly on the dorsal line. That would allow ad and pd bristles to be within a few degrees of each other. Sorry to be slow to understand this.  |
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| javanerkelens |
Posted on 26-01-2010 23:43
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Member Location: Netherlands Posts: 2962 Joined: 18.10.07 |
Maybe a little exaggerated (mostly the setae is standing nicely in a ad and pd position) But sometimes they have a little differents. I just mean to say, it is not always precise 90 degree. There is some variation to it. When i look at the chaetotaxy from 5 the same species, the chaetotaxy can be a bit different each species. But mostly the numbers of hairs are the same (for instance 1av+2ad+1pd+7pv) Sometimes the av is close to the ad and sometimes they are far apart and you almost think the av it is a pv....  Nice hobby we have.... Joke Edited by javanerkelens on 26-01-2010 23:46 |
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| Stephen R |
Posted on 26-01-2010 23:58
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Member Location: Clitheroe Lancashire UK Posts: 2396 Joined: 12.06.09 |
Enough to drive you round the bend . That pd looks to me to be almost exactly opposite to the femur when the knee is flexed. Thanks again for being so patient. Stephen. Edited by Stephen R on 26-01-2010 23:59 |
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| oxycera |
Posted on 27-01-2010 09:27
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Member Location: Barnsley, South Yorkshire Posts: 251 Joined: 31.12.09 |
very useful thread |
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