• Kingsbury, P.D.
  Forest Pest Management Institute
  

Treatment of small lake with 140 g fenitrothion/ha had little overall impact on lake biota. Little pesticide reached the deeper parts of the lake and persistence in surface waters was approximately one week. Fish cages at the surface accumulated moderate quantities of fenitrothion without apparent effects, and fish below the thermolice accumulated little more than trace amounts. Surface population of zoo-plankton and phantom midge larvae, Chaoborus sp., were depressed for a short period. No substantial impact was found on benthic invertebrates, emerging insects or amphibians in the lake.