Funding provided by the
National Science Foundation


University of Tennessee
Clemson University
University of California-Davis
Iowa State University
Canadian Food Inspection Agency

Taxonomic key an interactive key to Chrionomidae



Adult thaumaleid.

Thaumaleid larvae on rock in madicolous habitat.

Solitary or seepage midges are a rarely collected and poorly known family of nematocerous flies. More than 150 species in seven genera are currently recognized, with representatives on all continents, except Antarctica. Immature stages are restricted to rocks covered by a thin layer of flowing water known as seepage or madicolous (= hygropetric) habitats (Sinclair 1996).

These microhabitats occur along rocky cascading streams and creeks, springs, waterfalls, and seepages. Thaumaleids are rarely collected, with larvae by far the most often encountered life stage.

Their dorsal integument is hydrophobic, enabling them to maintain their position in the water film. This morphological feature facilitates the characteristic lateral jerking motion that permits immediate family recognition of larvae. Thaumaleid researchers have been primarily concerned with the description of new taxa based on adults (almost entirely on male genitalia) from specific biogeographical regions.

Few attempts have been made to interpret relationships among species or genera and no formal phylogenetic analyses exist for the family. Generic concepts, especially in the Northern Hemisphere, are poorly defined. Knowledge of the immature stages is poor in comparison to other families of the Chironomoidea, with only the pupae of Trichothaumalea clearly diagnosed (Sinclair 1992, Sinclair & Saigusa 2002). Sinclair has over 20 years of experience working with thaumaleid systematics.

Thaumaleid larva.

Canadian Food Inspection Agency (PI Sinclair)

Dr. Sinclair, Canadian Food Inspection Agency