Caterpillar _MG_9330

Caterpillar _MG_9330
Originally uploaded by Royjackward.

This caterpillar (of the Orchard Swallowtail butterfly) rears-up when provoked and distends these two red horns, called osmeterium. From these horns it releases a powerful and pungent scent; a concentrated product from the sap of the citrus tree on which it has been feeding.