Dobsonflies live in fast-moving, non-polluted streams and rivers throughout the world, except Europe. Most live in temperate climates, but parts of Asia and Africa find dobsonflies in and near their waters as well.
Eggs
The eggs of the dobsonfly are laid in layered clusters above water. There can be up to1,000 eggs in a cluster, and they hatch in about one to two weeks of being laid, falling into the water.
Larva
The larvae, or hellgrammites, float in an air bubble in the water until they reach an optimum under-water environment to continue their development, usually under a rock. The hellgrammite sheds its exoskeleton 10 to 12 times in one to three years until it is ready to pupate.
Pupa
The larvae finds a safe place under a rock or leaves near the water to pupate. A dobsonfly pupa is able to defend itself, having legs, wings and mouthparts. This stage lasts about seven to 14 days.
Adult
The adult stage of the dobsonfly lasts about three days for a male and 10 days for the female. They are active at night and are attracted to lights. They die shortly after mating.
Benefits to Humans
Because they live in non-poluted waters, ecologists utilize them as a pollution barometer. Fishermen also value dobsonfly larvae as bait for bass.
Tags: lasts about, under rock