• Trial, Joan Garner
  University of Maine
  

The impact of Sevin-4-oil on aquatic insect communities of streams has been studied in Maine for several months after application of the chemical for spruce budworm control. Courtemanch and Gibbs (1977) and Trial and Gibbs (1978) reported on the effects of a single application of Sevin in 1976. Courtemanch and Gibbs (1977) also studied streams sprayed with Sevin in both 1975 and 1976. Courtemanch and Gibbs (1977) and Trial and Gibbs (1978) noted dead and dying Plecoptera and Trichoptera in the stream immediately after spray. Reductions in standing crop of Ephemeroptera, Plecoptera, and Trichoptera occurred in some or all the streams studied in these two independent projects. The Plecoptera in samples from all Sevin sprayed streams were reduced to zero after spray and remained at that level for the duration of the studies. Courtemanch and Gibbs (1977) found that samples from streams sprayed in the spring of 1975 were devoid of Plecoptera in May of 1976.