Pipevine swallowtail caterpillar

Description:

Adults: The upper surface of the hind wings are an iridescent blue or blue-green with pale, arrow-head markings. Males have brighter metallic regions than females. The underside of the hind wing has seven orange submarginal spots surrounded by iridescent blue. Both surfaces of the fore wings are black or dull blackish-brown. Individuals are smaller and hairier in northern California. (information from Wikipedia) Larvae: Caterpillar is quite distinctive, may be a mimic of the tropical onychophorans, called velvet worms. Dark brownish black (occasionally smoky red) with soft fleshy tentacle-like projections, usually red-orange dorsal warts over abdomen. Tentacles on T1 twice as long as those on following segments. (information from BugGuide)

Notes:

Larvae feed on Aristolochia species. These include "Pipevine" or "Dutchman's Pipe", Aristolochia species (tomentosa, durior, reticulata, californica), as well as Virginia Snakeroot, (Aristolochia serpentaria). Larvae presumably take up toxic secondary compounds (including Aristolochic acid) from their hostplant. Both larvae and adults are believed toxic to vertebrate predators, and both have aposematic (warning) coloration. (information from BugGuide)