• Julin, Arnold M
  U.S. Fish and wildlife service
  
• Gramlich, Francis J.
  U.S. Fish and wildlife service
  

A number of candidate pesticides for control of spruce budworm in Maine have been evaluated ¡n an attempt to find a chemical that is effective yet causes a minimum damage to non target organisms. In 1977, the organophosphate Orthene was applied experimentally to 60,000 forested acres near the Lily Bay area of Moosehead Lake in Piscataquis County, Maine. An evaluation of the effects of Orthene @ on songbird brain cholinesterase activity was done by the U.S. Fish and Wildlife Service with assistance from State of Maine personnel. Ludke et al. (1975) stated that analyses of brain cholinesterase activity can be a reliable tool to measure effects of organophosphate insecticides fed to birds; and Peterson (1976) and Zinkl et al. (1977) used brain cholinesterase activity to measure response to organophosphates in birds exposed to aerial applications.