Field evaluation of fenitrothion, permethrin, and chlorpyrifos for protecting white spruce trees from Spruce beetle (Coleoptera: Scolytidae) attack in Alaska [Picea glauca, Dendroctonus rufipennis]

Concentrations of 0.25 and 0.5% permethrin, 0.5 and 1% chlorphyrifos, and 1 and 2% fenitrothion provided acceptable protection for 4 months to white spruce, Picea glauca (Moench) Voss, trees from attack by spruce beetle, Dendroctonus rufipennis (Kirby). At 16 months after application, 0.25% permethrin and 2% fenitrothion still provided adequate protection. Residues from insecticides in a stream adjacent to the treatment site were insignificant from 0 days to 15 weeks after application. Movement of residues from the treated trees into the soil from rain runoff was minimal.