Michael Boppre, Ph.D is studying some mimicking insects of the short-tempered, stinging, yellow and black wasps we're all familiar with.
Typically, we assume that imitators of wasps are trying protect themselves from predators like birds and frogs. These predators learn from the painful experience of attempting to prey upon stinging wasps, and after which they avoid them, as well as their mimics. Thus, for more than 150 years, “wasp mimicry” seemed to have had a good explanation.
Wasps are predators themselves--they hunt insects as food for their larvae. Could the mimics, by looking just like wasps, protect themselves not only from learning birds and other vertebrate predators but also from the very wasps they're imitating? Instead of signaling to birds that they are wasps (as assumed so far), it seems plausible that the similarity is sufficient to cause wasps to react to such mimics as if they were just other wasps.
The new explanation is new and still being studied and researched, and although it seems a minor detail about insect mimicry, it could change everything we thought we knew about it. Read more about this intriguing hypothesis at Entomology Today.