Dobsonfly
Guides
Corydalidae
Dobsonflies and Fishflies
Corydalidae is a family of large megalopteran insects commonly known as dobsonflies and fishflies. Adults typically exceed 25 mm in body length and possess long filamentous antennae—feathered in male fishflies—and four large, translucent, smoky-grey wings with the anterior pair slightly longer than the posterior. The family is divided into two subfamilies: Corydalinae (dobsonflies), whose males bear distinctive elongated mandibles used in combat, and Chauliodinae (fishflies), whose males have normal mandibles. Aquatic larvae, called hellgrammites, are predatory and possess strong sharp mandibles and abdominal branchial filaments for respiration. They develop over one to three years before leaving water to pupate in terrestrial chambers dug under stones or logs.
Corydalus
dobsonflies, hellgrammites (larvae), go-devil, grampus
Corydalus is a genus of large flying insects in the family Corydalidae, commonly known as dobsonflies. The genus contains approximately 35 species endemic to North, Central, and South America. Adults are among the largest winged insects in their range, with wing lengths reaching up to 85 millimetres. The genus exhibits pronounced sexual dimorphism: males possess greatly elongated, sickle-shaped mandibles used in male-male combat and to grasp females during mating, while females have smaller but still formidable jaws capable of delivering a painful bite. The aquatic larvae, known as hellgrammites, are predatory and serve as important indicators of stream health.
Corydalus luteus
hellgrammite, dobsonfly
Corydalus luteus is a species of dobsonfly in the family Corydalidae, found across the Americas from the United States through Central America to South America. Adults are large, spectacular insects with prominent mandibles—greatly elongated in males, shorter but powerful in females. The larvae, known as hellgrammites, are aquatic predators inhabiting streams and rivers. The species is attracted to lights at night and is occasionally encountered by entomologists during field surveys.
Corydalus texanus
Western Dobsonfly
Corydalus texanus is a large megaloopteran insect commonly known as the Western Dobsonfly. Adults are among the largest winged insects in their range, with males distinguished by elongated sickle-shaped mandibles used in combat with rivals. Females possess shorter but powerful jaws capable of delivering a painful bite. The aquatic larval stage, known as hellgrammites, are predaceous and serve as important indicators of stream health. Adults are attracted to lights and may be observed near water bodies at night.