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South-east Norway
25. 09 2016
Dirt-road, mixed forest
About 8 mm.

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b

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c

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e

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Can you give us a photo of the radial node of the wing to check for any setulae?

also are there stpl 1:2 or 2:2

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Mydaea cf. orthonevra.
Katepisternales are 1:2 ( pictures 2 & 4 show only 1 anterior ks seta) and pra seems longer than post. notopleural (this point had to be confirmed) --> M. orthonevra / urbana.
Then the trochanters seems to be yellow, not brown and fore tibia without p. seta --> M. orthonevra.


If the pra is shorter than p. ntpl, Mydaea electa would be the alternative (this was the more frequent Mydaea species I Identified for the Swedish Malaise Trap Project).

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I was too quick to release the fly...but thank you so much to both of you for your responses !

Rosevinge

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My first guess was Mydaea also?

I guess you don't have the fly to continue for confirmation, there are a couple of other points I wanted to check also, do you have any more photos that you can add?

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No, i don`t have the fly, but I do have some more photos. So please tell me which parts of the fly do you want to see in close-ups.

Rosevinge

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1. to be sure its a Mydaea it must have setulae on the radial node of the wing, do you have any photos of the ventral side? I can't see any on this photo

2. I can see 1 anterior stpl seta (as stated by Stephane) however I( am not sure if there is a bristle socket beneath some species have a weak 2nd stpl seta, I can't be sure at this resolution?

3. The aristal hairs appear to be as long as the width of the postpedicel so that's ok

4.
The number of av on tibia 3 is also helpful to eliminate another species, I am not sure if this is 2 or 3? photo 3 looks like 2 but there may be another behind it?

I guess I'm very cautious Stephane has covered it well but a positive id needs evidence

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1. Sorry, I don`t have any photos of the ventral side.
2.

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b

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4. difficult to say...
Thank you for trying to identify this fly!
Perhaps I have misunderstood what you are looking for. I admit I`m struggeling With the terminology, espcially the abbreviations...

Rosevinge

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Ok

I enclose a link to show the setulae - for the future
http://www.dipteristsforum.org.uk/p2584-2010-08-11-01%3A48%3A22.html
always take a photo
2
it looks like its a 1:2 stpl, a higher mag shows a dark mark rather than a bristle socket
next we move to tibia 3 photo 4 above, the bristles on the right side of the tibia seem to be 2av, 2 ad
I need a close up where the bristles do not overlap, it looks like there are 2 upper ones and 2 lower ones, I want to check that the 2 lower ones are not 3 lower ones (3av)

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Maybe?

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Every shot throws up a curve ball, 2 av obvious, the 3rd one could still be a setae from the abdomen it's not clear enough

Can you try the other leg?

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I`ve run out of pictures and I don`t think this closeup will help..... but it is OK.
I call it:" Mydaea orthonevra ?"


Rosevinge

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Looks like 3, it was hiding
Right lets try 1 more thing, I enclose a photo from another thread which shows where the pra and 2nd ntpl is, thanks to Stephane it is very clear

Have a look for a photo that shows the length of the pra and 2nd ntpl seta

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Assuming
Mydaea (Robineau-Desvoidy)


This genus is distinguished from its allies by having the third wing-vein setulose at base, fourth not curved forward at apex, tibia 3 without calcar, penultimate abdominal sternite in female with a number of short bristles, eyes of male subcontiguous, prealar bristle present, prosternum bare, face not buccate.

Assuming stpl 1:2
Tibia 3 with 3 av setae – orthonevra f. detrita, stpl 1:2, pra longer than 2nd ntpl seta, tibia 3 with 3 ad (Hennig) and 2 ad (Gregor et al)
3av for orthonevra f. detrita in both Hennig, Gregor et al., 2002


Fauna Europea
Norwegian mainland for Family Muscidae:


Norway + 3 species

Mydaea nubila Stein 1916 - Halteres mostly darkened, Hennig gives 2 p setae on tibia 2 I don't know the colour of the legs, he says that tibiae can be yellowish but nothing for the femora
Mydaea palpalis Stein 1916 - Legs black
Mydaea sootryeni Ringdahl 1928 - Legs black

Last 2 from Gregor et al., 2002

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Mydaea orthonevra is in the Norwegian Red List assessments of species, but in the category: not evaluated.(NE)

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2

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Thanks for the photos, I can't go any further