Catalpa Sphinx

Ceratomia catalpae — the catalpa sphinx — is one of about 200 species in family Sphingidae (the hawk moths) and the species responsible for the famous 'CATALPA WORM' of the southeastern US. The species is widespread across the southeastern US from southern Pennsylvania south through the eastern US to northern Florida and west to Texas, with distribution closely tied to the geographic range of catalpa trees (Catalpa bignonioides — southern catalpa; Catalpa speciosa — northern catalpa). Adults are 6-7 cm wingspan, modestly-marked gray-brown moths with subdued patterns — the adults are visually unimpressive compared to other hawk moths. The species' major significance comes from THE LARVA — the famous 'CATALPA WORM'. Larvae are 5-7 cm long when fully grown, bright GREEN OR BLACK (color polymorphic — both color forms occur in the same broods), with bold YELLOW LATERAL STRIPES along each side, and the species' diagnostic feature: a prominent BLACK DORSAL HORN on the eighth abdominal segment (the typical sphinx-moth horn). Larvae feed exclusively on catalpa tree leaves and can completely defoliate catalpa trees in outbreak years (regular outbreaks occur every 3-5 years across the southeastern US). The defoliation is conspicuous but rarely fatal to host catalpa trees (the trees re-leaf after defoliation). The species is one of the most-prized FRESHWATER FISHING BAITS in the southeastern US. Catfish and bass cannot resist the catalpa worm — the worm's size, movement, and natural occurrence in southeastern US streams (where wind-blown caterpillars commonly fall into the water and become available as fish food) make it irresistible to large predatory freshwater fish. Catalpa worms are particularly valued for: catfish (especially channel catfish and blue catfish — catalpa worms are widely cited as the single most effective live bait for big catfish), largemouth bass, smallmouth bass, sunfish, and bream. The fishing-bait significance has made the catalpa sphinx one of the most-cited cases of an insect being DELIBERATELY CULTIVATED BY HUMANS for its larval stage. Across the southeastern US (especially Tennessee, Kentucky, Georgia, Alabama, Mississippi), fishermen have for over a century PLANTED CATALPA TREES specifically as 'CATALPA WORM FARMS' — reliable sources of bait worms for fishing. Old catalpa farm plantings (sometimes 50-100+ years old) are still maintained by multi-generational fishing families. Live catalpa worms are also commercially sold at southeastern US bait shops during the summer worm season. The species is harmless to humans (no urticating hairs, no venom — even the dorsal horn is decorative) and is a flagship example of insect-human cultural interaction in southeastern US natural history.