Female Dobson Fly
Common Names: Dobsonfly, Western Dobsonfly
Scientific Name: Order Neuroptera, family Corydalidae, Corydalus cornutus
Size: Body--1 1/2", wingspan--3 1/2"
Male Dobson Fly
Identification: Head is almost round, prothorax is squarish and narrower than the head, wings are mottled, translucent and grayish color with dark veins. Mandibles of the male are half the length of the body, curved and tapering to the tips, and are held crossing one another; the female's mandibles are shorter and capable of biting.
Biology and Life Cycle: Rounded masses containing hundreds of eggs are laid on rocks and branches near water. Each mass is coated with whitish secretion. Larvae drop or crawl to water to live. They crawl out of water to pupate under logs and stones where they overwinter. Adults emerge in early summer. Complete metamorphosis.
Habitat: Live around water, especially fast-moving, well oxygenated water.
Feeding Habits: Adults eat very little if any; aquatic larvae prey on water insects.
Economic Importance: Larvae are good fish bait.
Natural Control: Fish.
Organic Control: None needed, beneficial.
Insight: Fisherman cherish the larvae, called hellgrammites, as bait. Adults are beautiful and fascinating. The male's large crossed jaws look fierce, but are only used to hold females during mating and are useless as weapons. The females have shorter jaws and pack a more powerful nip. Neither is dangerous. Adults are attracted to lights at night