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Stony Stratford, Bucks (UK), 22nd September 2010. On old wooden fence below willow, ash and sycamore. Grazing cattle and water close by.

Would appreciate help with identification (unfortunately this is the only pic I have so no dorsal view):

Bruce :)

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S. affinis

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Thanks for your help Ruud - much appreciated.

Bruce

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Could anyone tell me what separates Suillia affinis from other Suillia species? That is, what is specific to this species which other Suilia sp. do not have.

I find Bruce's fly looks different to the one I had which is also S. affinis, the main differences being the bristles on the hind femur and the many bristles on the ventral area between legs 1 and 2.

Could this be a difference between males and females? I'm trying to learn what I should be looking for so would appreciate any help with this.

Janet :)

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It is not possible to give 1 characteristic, which is affinis separating from all other species of affinis. It is rather a combination. Affinis is rather common.

the sides of the thorax (mesopleuron etc) is bristle-free.
the arista of the antenna is long plumose
the animal is fairly large, but as large as gigantea, which is 9-13mm. Affinis is between 5-9mm.
In order to be sure it is not umbratica I check the colours of the bristles on the back-side of the head near the neck. If they are yellowish it is affinis.

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Janet, try to get the key of P. Withers. Proc. Trans. Br. Ent. Nat. Hist. Soc. 20, 1987. It is very handy and it will be quite easy to separate the common species of Suillia.

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Add please also this one: Keys to The Insects of The European Part of The USSR. Diptera and Siphonaptera (Keys to the Fauna of the USSR S.), part 2. G. Ya. Bei-Bienko editor. Publisher: Brill (Dec 1989).
The Suillia key is at following pages: 529-537 !.
but: S. nudipes Czerny is S. flavifrons and S. flavifrons sensu Gorodkov is S. parva Loew.
Andrzej

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Thank you Ruud and Andrzej!

That is a good start to my learning about these, I will see if I can find the reference works mentioned either online or secondhand books listed online.

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Well, I found the one you mentioned Ruud, but there's a full bound set from 1952 to 2001 of 50 volumes. If anyone wants to spend £250 I would say it's a good find! Item no. B1907

http://www.pemboo...sed01.html

Alas Andrzej, I only found the first edition of The Insects of The European Part of The USSR, both in Russian and translated versions. It would be good to have that too, and the cost is not so bad but too much for me. Someone else might be interested though, from Abe Books.

http://www.abeboo...7&y=19

(got the wrong link)

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Why not pm Mr. Withers and he might send you a copy of the key ;)

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Indeed! It is easy to get a copy. The article is not too big

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read it: http://books.google.com/books?id=dsoUAAAAIAAJ&pg=PA510&lpg=PA510&dq=Gorodkov+helomyzidae&source=bl&ots=FjvfZJn9f_&sig=PMMQipB1k5q0iiCUxMhMzOV0TdM&hl=pl&ei=GAWmTIv3N83Nswba-eSxCA&sa=X&oi=book_result&ct=result&resnum=1&ved=0CBcQ6AEwAA#v=onepage&q=Gorodkov%20helomyzidae&f=false !
Sorry but I have this one in Russian only ;)
Andrzej

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That's not a bad idea Hyperbolizer! Hi Phil, if you wouldn't mind sending me a copy it would be much appreciated! :D

Andrzej, brilliant! I found it on google books in English!!!!!

http://books.goog...mp;f=false

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I'll see what I can muster...

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If it's not too much trouble, thanks! I have just snipped 56 pages from the keys on google books, of course some of it overlaps. I need to trim off the unnecessary stuff on the pages, they are copied to my Pictures location in jpeg so I can place them all in one folder and view in succession. :D