Threesome? - BugGuide.Net

Interesting,

but it looks like there are a bunch of those little flies, both on the bug, as well as on the Robber Fly (I count up to five, depending on the photo). Was the Asilid still alive?

… Hartmut Wisch, 7 June, 2007 - 5:20pm

Dead

It was quite dead, but then the Robber fly didn't move for a good 10 minutes while I was photographing. :-)

More like 20, but I was interested in varieties not a head count.

… Jim Kramer, 7 June, 2007 - 5:37pm

Yes,

and I was thinking about putrefaction attracting all those little flies; seems to be more than one species.

… Hartmut Wisch, 7 June, 2007 - 6:52pm

If,

If you look at the link listed by Stephen Luk under my first image it mentions that this type of Milichiid fly is attracted to the defensive chemicals released by the asilid. It did not "appear" to have been dead a long time. There is some variation in the small flies' size, but must of the size and color differentiation I would attribute to whom had been feeding the longest. Some looked as if they would burst.

… Jim Kramer, 7 June, 2007 - 7:14pm

Just to clarify:

Asilidae= Robber Fly
Milichiidae = cleptoparasitic fly
Pentatomidae= Stink bug

If I understand correctly, the Robber Fly is alive, the Stink Bug is dead, and the stink bug's defensive chemicals may have drawn the Milichiid fly

… Chuck Entz, 8 June, 2007 - 11:55am

Sorry,

I clearly mixed that up. Thanks. And yes.

… Jim Kramer, 8 June, 2007 - 12:44pm

Fascinating -

I should examine some old photos, vaguely recall having seen these flies when photographing Robber Flies in Lockwood Valley, CA.

… Hartmut Wisch, 7 June, 2007 - 7:28pm