The red color results from an iron containing compound, haemoglobin, that is in the midge s blood. The haemoglobin al-lows the larvae to respire under low dissolved oxygen conditions in the bottom mud. The lar-val stage can take from less that 2 to 7 weeks depending on water temperature. Larvae transform into pupae while still in their tubes. After 3 days, pupae actively swim to the sur-face, and adults emerge several hours later.
Adults mate in swarms soon after emerging.
During summer, the entire life cycle from egg to adult can be completed in 2 to 3 weeks. In the fall, larvae do not pupate, but they suspend development and pass through the winter months as mature larvae. Pupation and emergence of adults occurs the following spring in late March or early April. Several more generations of midges will be produced throughout summer, resulting in mass emergences of adults. In each generation, adults will typically emerge in large numbers for several weeks.