Pipevine Swallowtail caterpillars

Description:

Pipevine Swallowtail, Battus philenor, caterpillars defoliating on Virginia Snakeroot, Aristolochia serpentaria. This is the biggest mass of large PVST cats I've seen!The females often lay so many eggs on my cultivated plants that they are completely defoliated. First the caterpillars eat the foliage, then the stems, and then even the fruits, which are rather dry capsules. I've tried offering hungry cats the related Hexastylis (same family), but they refuse it. A lot of the caterpillars do not survive to pupate when this happens, and I've had to start culling them in order to get some chrysalises. Big crops of cats like this seem to happen every other summer.Battus_philenorPCSL20102A