Waipio Valley Stream Restoration Study

Insects: Introduced Species

Scientific name: Cricotopus bicinctus
Common name(s): Non-biting midge

Cricotopus bicinctus

Status: Introduced

Habitat: Riffles in streams

Preferred Area of Stream: Found in sections of flowing streams such as runs and riffles.

Range in Hawai‘i: All main Hawaiian Islands

Diet: Herbivorous, feeds on algae and decaying vegetation.

Predators: Predatory aquatic insects and native and introduced fish.

Fact: Cricotopus bicinctus adults are easily distinguished from all other Hawaiian midges by its bright yellow stripes on its abdomen. This introduced midge is now one of the most common aquatic insects in running waters in the Hawaiian Islands . Many larval aquatic insects leave the security of their rocky habitats in the early morning and late evening and float downstream to a new habitat; this phenomenon is called stream drift. In Hawai‘i, Cricotopus bicinctus has been shown to drift more so than native stream insects, why might this be?