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I don't think we can be sure that this is Hylemya, and indeed I'm not sure which family it is! Either Muscidae or Anthomyiidae as Ed suggested.
Hylemya is in family Anthomyiidae, and I can't see any reason why this isn't Hylemya, but I can't see anything to confirm it either! I think this is a female fly (male Hylemya have the eyes meeting at the top of the head), which means that if it is Hylemya it can't be safely distinguished anyway.
Maybe someone who knows this group better than I can say more about it, but it's a tricky one.
Entomologist and biological recorder
Steven Falk has kindly commented on this image on Dipterists Forum. He suggests Hylemya, probably vagans, though the female of nigrimana is apparently indistinguishable. Both occur in Warwickshire.
In which case well done to Chris for getting the correct genus, and apologies for casting doubt on it! Chris: would you like to add a further ID for genus Hylemya so we can agree with it?
Thanks martin, probably more by luck than judgement, Regards Chris
Chris Brooks - www.dragonfly-images.co.uk
My Flickr site - www.flickr.com/photos/ceb1298
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