The Eastern Black Swallowtail Butterfly caterpillar (Papilio polyxenes) is common to North America. It is found in fields, marshes and suburban / urban environments.
The caterpillar feeds on members of the parsley family -- Queen Anne's Lace, Parsnips, Celery and Dill.
The caterpillar uses two strategies to avoid predation. First, it absorbs toxins from the plants it eats, making it unpalatable to predators. Second, it has a orange gland, called an osmeterium, that it everts from the top of it head when disturbed. The osmeterium releases a foul-smelling chemical that deters predators.
The caterpillars overwinter in the chrysalis stage. Adults emerge in the spring. There may be several broods throughout the year.
Adults feed on nectar from flowers such as red clover, milkweed and thistle. Males are territorial and fiercely defend their territories.
