Angler-bait
Guides
Corydalus cornutus
Eastern Dobsonfly, Hellgrammite (larval form), Go-devil, Grampus
Corydalus cornutus, the eastern dobsonfly, is among the largest insects in eastern North America, with adults reaching 140 mm in length and wingspans up to 130 mm. The species exhibits pronounced sexual dimorphism: males possess elongated, sickle-shaped mandibles up to 40 mm long used in combat with rivals, while females have shorter, powerful mandibles capable of delivering a painful bite. The aquatic larval stage, known as hellgrammites, are apex invertebrate predators in fast-flowing streams, feeding on other aquatic insects for one to three years before emerging to pupate in terrestrial soil chambers. Adults are short-lived, non-predatory, and primarily nocturnal, attracted to lights near waterways.