These flies usually live in damp places, including extreme habitats such as sulfurous hot springs, highly alkaline or saline water, and pools of crude petroleum. Adults may feed on the nectar and pollen of flowering plants in moist prairies or wetlands, microscopic algae or other small organisms. Larvae feed on decaying vegetation, on other arthropods, or aquatic plants. They have been used by Indigenous people for food, and are important for waterfowl.
Representative Genera and Species:
Pollinator Life Cycle:
They have four life stages: egg, pupa, larva, and adult. The cycle may be completed in as few as 2-3 weeks. One to several generations may be produced annually. Females of many species lay their eggs in water, and larvae are mostly aquatic.
The status of Canadian species has not yet been assessed, and none are legally protected.
These small flies are 1-11 mm long, varying in shape and overall appearance. Many species have a prominent bulging face, with females usually larger than males. They are typically dull and dark coloured with wings that sometimes have dark markings. Antennae have three segments, the third one rounded in shape.
Adults are common in fresh and salt-water shoreline and wetlands habitats: ponds, lakes streams, rivers, marshes etc. Often in hostile habitats such as salt lakes, pools of crude petroleum, sulfurous hot springs, and highly alkaline or saline water.
- British Columbia
- New Brunswick
- Northwest Territories
- Nova Scotia
- Prince Edward Island
- Fescue Prairie
- Mixed Grass Prairie
- Tall Grass Prairie