Location: Southeast Arizona desert scrub at 3500 feet elevation. N32 deg, 18.3min; W110 deg, 21.5 min
September 13, 2010 10:15 pm
Please identify this caterpillar.
Signature: Bob Evans
These are the caterpillars of the lovely Pipevine Swallowtail, Battus philenor, which you can verify on BugGuide which indicates: “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.” We don’t normally think of them as a desert species, so your letter is quite welcome.