Non-biting midges

Chironomus is a genus of non-biting midges. There are at at least 647 Chironomus species worldwide, about 90 species in North America north of Mexico, and at least 34 species in Minnesota. They occur worldwide, on every continent except Antarctica. They are very common and are found almost everywhere.

The larvae are aquatic. They live in the sediment at the bottom of bodies of water. Many construct tubes of debris in which they live. They are highly tolerant of pollution. Some of them are red and are called bloodworms.

Adults are short lived. They frequently occur in large swarms. As the family name suggests, they do not bite.

The exoskeletal plate covering the thorax (pronotum) is widest in the middle and is notched. On most species, the upper part of the face has a pair of minute bumps (tubercles) in the middle. The antennae on the male have eleven segments. This combination of features helps to identify this genus, but each of these features is shared by at least one other genus of midges.

Many of these species are nearly impossible to identify with a photograph. Some can be identified only by examining their giant chromosomes.

Sources

24, 27, 29, 30, 82, 83.

Biodiversity occurrence data published by: Minnesota Biodiversity Atlas (accessed through the Minnesota Biodiversity Atlas Portal, bellatlas.umn.edu. Accessed 1/3/2026).

The Minnesota Polution Control Agency (MPCA) has multiple records of this genus in every county in Minnesota. The counties in light green on the map have only MPCA records.