Polydamas is a common swallowtail in peninsular Florida and south Texas, with strays sometimes turning up much further north. They seem to be always on the wing, never stopping for long. This is the only one I was able to photograph, because it had stopped to lay a batch of eggs on a pipevine (Aristolochia sp.), the caterpillar host plant.

Boca Raton, Palm Beach Co., FL 6/28/2010.

Freshly laid eggs.

Boca Raton, Palm Beach Co., FL 6/28/2010.

The caterpillars are similar to those of the closely related Pipevine Swallowtail.

Key West, Monroe Co., FL 6/27/2010.