Chironomid midge larval densities were studied in Silver Lakes, from March-November, 1979. Midges of quantitative importance from Mar-May included species of Tanytarsus, Procladius and Chironomus. Chironomus decorus and Procladius spp. Were most prevalent from Jun-July with the former most abundant from August-November. Chemical abatement measures included the O-P insecticide Abate and 2 urea-type IGR's Dimilin and Bay SIR-8514. Applications of Abate at 0.28 kg AI/ha eliminated Tanytarsus spp from the benthic samples up to 2 wk post-treatment but had no effect on species of Procladius or Chironomus. Higher treatment rates, 0.33 kg/AI/ha and 0.56 kg AI/ha, similarly had no effect on larval numbers of Procladius or Chironomus (mainly Decorus). Dimilin and Bay SIR-8514 applied at rates of 0.11 and 0.28 kg AI/ha effectively suppressed adult emergence of species of Tanytarsus and Procladius for up to 2 wk posttreatment, but neither IGR was effective against the more pestiferous midge species C. decorus. Coinciding with the IGR treatments was a decline in larval numbers suggesting that the compounds possess larvicidal capabilities.