Southern catalpa is the species common to Alabama. Northern catalpa is very similar to southern catalpa. Both catalpas have been widely planted and have become established outside their natural habitats. Adults are strong fliers, but fly mostly at dusk or night and are not commonly seen. They are deposited in mound-like masses on the undersurface of leaves.
Coloration is somewhat variable, and there appear to be two primary color phases, dark and pale.
The sides are yellowish with some black spots and vertical lines. In the pale phase, the solid black band is lacking. Sides of the larva are generally greenish yellow. The catalpa sphinx overwinters as a pupa in the soil under or near trees infested the previous season. In spring, pupae work their way to the soil surface and moths begin to emerge shortly after host trees have leafed out.