The Dobsonfly is a large, aquatic insect found in temperate regions around the world. It is easily recognizable by its long, thin wings and large mandibles. The larvae of the Dobsonfly are aquatic and feed on small aquatic organisms. The adults are nocturnal and
From Wikipedia
Dobsonflies are a subfamily of insects, Corydalinae, part of the Megalopteran family Corydalidae. The larvae are aquatic, living in streams, and the adults are often found along streams as well. The nine genera of dobsonflies are distributed in the Americas, Asia, and South Africa.