Catawba worms are actually not worms at all, they are the larvae stage of a Moth Ceratomia catalpa that only eats the leaves of a "Catalpa/Catawba" tree.
The larval stage of Ceratomia catalpa is known as the catalpa or catawba worm. When first hatched, these larvae are a very pale color, but become darker toward the last instars. The yellowing caterpillars will usually have a dark, black stripe down their back along with black dots along their sides.
They grow to a length of about two inches and feed on the leaves of the Northern catalpa and, more commonly, the Southern catalpa. The fully developed caterpillar has a conspicuous black spine or horn on the back at the insect's rear. Catalpa sphinx moth caterpillar is usually plump with forage and are beautiful when mostly yellow with black lines and spots in the last color phase. They are highly desired by fisherman as bait.
Family: Sphingidae Subfamily: Sphinginae Identification: Forewing is yellowish brown with no white markings and indistinct black lines and dashes. Cell spot is gray with a black outline. Hindwing is yellowish brown with obscure lines. Wing Span: 2 9/16 - 3 3/4 inches (6.5 - 9.5 cm).
Tip! Learn Catapa Sphinx life cycle, habits, and importance at Ag.auburn.edu.