Fishflies Dobsonflies and Alderflies: Megaloptera

Megalopterans live in North, Central, and South America, South Africa, Madagascar, and parts of Asia and Australia. Most species are found outside of the tropics. There are about 300 species of megalopterans worldwide, 43 of which are found in the United States and Canada.

Aquatic larvae live in standing or flowing waters, including streams, spring seeps, rivers, lakes, ponds, and swamps. Some species burrow in soft mud or sand, while others hide in crevices or under stones or bark. Adults are found on vegetation beside aquatic habitats.

The larvae actively hunt a wide variety of small aquatic insect larvae, crustaceans, clams, and worms. Adult alderflies may feed on flowers, while female dobsonflies and some fishflies take in plant sap or other fluids. Male dobsonflies do not eat.

No megalopterans are listed as endangered or threatened, but like all species that live only in small geographic areas, their populations are vulnerable to logging, pollution, and other human activities, as well as to natural events that lower water quality.