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I'd be interested to have your comments on this picture I took some weeks ago of a Thomisus onustus spider feasting on a bee. But what interests me most are the small flies in attendance. I'd be interested to know what they are and especially what they are doing in what would seem to be a thoroughly uncomfortable position! Thanks in advance, Sarah

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The flies are probably Milichiidae. See also:

http://www.sel.ba...-biol.html

This site is set up by Irina Brake, who can probably tell you much more about the behaviour of these flies.

Jan Willem

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Thanks Jan. I've taken a look at the site and it certainly looks as if they are Milichiidae. Yet another example of the extraordinary richness and adaptive powers of the Diptera. I've sent a copy of the photo to Irina for her confirmation, if she adds anything of interest, I'll post it here. Thanks again, Sarah

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They are almost certainly Desmometopa. Species of this genus are often found on bees that have fallen prey to spiders (either crab spiders or in webs), robber flies or hunting bugs.

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Thanks Paul. I find this behaviour quite fascinating and wish I'd managed to get more photos of the flies themselves, rather than just as an accompaniment to the main drama. Hopefully though I will come across them again, Sarah