Common Name: Catalpa sphinx
Scientific Name: Ceratomia catalpae (Boisduval)
Description: This caterpillar is one of the “hornworm” species, having a prominent black spine on the back end of the body. The caterpillar has a shiny black head and grow up to 3 inches long. Although body coloration and markings change as caterpillars grow, lengthwise yellow or green and black stripes become more apparent in larger caterpillars. This night-flying adult hawk moth has long, narrow gray or brown wings, which have a wingspan of about 3 inches, and robust, spindle-shaped bodies.
Hornworm caterpillars of the whitelined sphinx, Hyles lineata (Fabricius), feed on leaves of apple, azalea, chickweed, elm, evening primrose, portulaca, purslane, Virginia creeper and many other plants. Caterpillars grow up to 3 1/8 inch long, have yellowish-orange heads and their bodies are generally green with two black stripes along their sides. A black form with yellow stripes also occurs. Adult moths have a wingspread of about 3 inches, with long narrow brown and black forewings marked
with white veins, borders and a broad white and stripe running across the middle. Hind wings are dark brown with a rosy-white band across the middle, and the moth’s body is brown with white stripes on the head and thorax, and bands of black and white spots on the abdomen. These moths fly in daylight and evening hours, with hovering flight resembling that of humming birds as they sip nectar from flowers. This is one of the most commonly observed sphinx or hawk moth species.
Life Cycle: Winter is spent in the pupal stage, which appears naked, brown and spindle-shaped, 2 to 3 inches deep in the soil. Adult moths emerge in the spring and mate. Female catalpa sphinx moths lay clusters of up to 1,000 white eggs on catalpa tree leaves, usually in April or early May. Tiny caterpillars hatch from these eggs in about 10 to 14 days and feed together (gregariously) for the stages (instars). Caterpillars molt several times during development before they crawl down the tree trunk and pupate in the soil. Adults emerge several days later. There may be 4 to 5 generations per year in Texas.
Habitat and Food Source(s): Caterpillars have chewing mouthparts. Adults have siphoning mouths. Caterpillars feed on leaves only of catalpa trees. Caterpillars can be collected from host plants by hand-picking. They can be used live or frozen as fish bait. Adults are attracted to lights.
Pest Status, Damage: Catalpa trees are occasionally planted intentionally to produce caterpillars, sometimes called “catawba worms” for fish bait; caterpillars, immature stages of a hawk moth, feed on leaves. High numbers of caterpillars can defoliate ornamental catalpa trees, making them appear unsightly; medically harmless.
For additional information, contact your local Texas A&M AgriLife Extension Service agent or search for other state Extension offices.
Literature: Metcalf et al. 1962; Swan & Papp 1972; Thomas 1968.