Good morning, the subject can be a dipter of the family of Lonchaeidae - Silba sp. o Muscidae - Hydrotaea chalcogaster?
Thank you.
Photographed in Grosseto (Italy) 22/06/2014.
I was also in doubts. Well, if Iain wrote that it is not his charge, than it should be mine. In this case Ophyra chalcogaster seems to me a reasonable guess.