Black Flies

Benthic Macroinvertebrates

Sensitive Benthos

Moderately Tolerant Benthos

Pollution Tolerant Benthos

Black Flies (University of Alberta, Department Biological Sciences)

Blackfly larvae

Metamorphosis:

complete (see our life cycle page for more information)

Larvae:

small, worm-like and bulbous at one end: when out of water, they fold themselves in half while wiggling; color varies from green, brown, gray, but usually black; length up to 1/3 inch.

Reproduction:

females deposit eggs on submerged vegetation or other debris.

Adults:

fly-like; known as a serious pest because they inflict painful bites to warm-blooded animals.

Food:

larvae eat organic debris filtered from water; adult females of many species feed on blood.

Scientific Name:

Class: Insecta
Order: Diptera
Family: Simuliidae

Adult blackfly drawing (Penn State Unversity Entomology Dept.)

Black Fly adult

Indicator Role:

Black flies are found under rocks in swiftly flowing streams, but also sometimes indicate too many nutrients (nitrogen and/or phosphorus) in the water.

Information Source:

McDonald, B., W. Borden, J. Lathrop.1990. Citizen Stream Monitoring: A Manual for Illinois. Illinois Department of Energy and Natural Resources, ILENR/RE-WR-90/18. Springfield, Illinois.