Tony T wrote:

I think we can put this in the same league as the "Alligator Bug" (Homoptera: Fulgora laternaria), the head of which does look like an alligator and would be great mimicry apart from the discrepancy of habitat and size between the model and mimic.

Tony T wrote:

Need a photo of a Rhagoletis from behind
According to Marshall "the wing-banding pattern....seen from behind.. makes the fly look remarkedly like a jumping spider (the bands look like spider legs)"
Who wants to tangle with a jumping spider?

Edit: Further reading indicates that the mimicry is to fool jumping spiders as these spiders are the major predators. "Greene et al. (1987) and Whitman et al. (1988) showed that Z. vittigera mimics jumping spiders and is significantly protected from these common predators on its host plant. During the fly's wing flicking displays, its wing pattern resembles the legs and the abdominal spots the eyes of a spider in its own territorial display."

See: Reference here

Tony T wrote:
This is a North American Physocephala sp. (Conopidae) that closely resembles a Potter Wasp (Hymenoptera: Vespidae: Eumeninae).



In fact, when I first saw this fly on a flower I thought it was a Potter wasp.
Length: 10.5mm excluding antennae. 19 September 2007, New Brunswick, Canada.