Toxicity of stabilized and unstabilized pyrethrins applied to western spruce budworm

Abstract

Stabilized pyrethrins were test in a laboratory spray chamber to provide information for planning field trials of this insecticide against the western spruce budworm (Choristoneura occidentalis Freeman). No significant differences were found in toxicity to instars 3 to 6. Stabilizers appear to have had no effect on basic contact toxicity. The commercial formulation of pyrethrins was as toxic as the laboratory formulated standard. Probably only slight residual activity can be expected. No effect on basic contact toxicity could be produced by increasing concentration through a range of about one order of magnitude.

Citation

Lyon, Robert L.; Robertson, Jacqueline L. 1971. Toxicity of stabilized and unstabilized pyrethrins applied to western spruce budworm. Res. Note PSW-RN-255. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 6 p