Pipevine Swallowtail caterpillar

Description:

Pipevine Swallowtail caterpillar feeding on Virginia Snakeroot, Aristolochia serpentaria. One reference I've read says that the caterpillars of this mostly tropical genus, Battus, mimic the odd invertebrates called Onychophorans (velvet worms), which includes Peripatus--these are supposed to be toxic. (Of course, these caterpillars themselves are supposed to be toxic, so it would be a Mullerian mimicry.) An interesting idea. How would the mimicry work in North America? Could neotropical migrant birds possibly remember encounters with velvet worms? Or is it just "evolutionary inertia", with the mimicry having evolved in the tropics and been carried along into the temperate areas with this one species. Interesting speculation is possible.Battus_philenorPCCA20040528-1962A