Northern California Pipevine Swallowtail subspecies (B. p. hirsuta) feeding on native California pipevine (Aristolochia californica). Sixth instar was a normal occurrence for our captive reared caterpillars. Our website: www.lianginsects.com/ (uploaded to www.lianginsects.com/general-insect-timeline/b-philenor-rearing-notes-72716-8316)