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Abstract
The toxicities of acephate, aminocarb, carbaryl, chlorpyrifos, chlorpyrifos-methyl, methomyl, mexacarbate, permethrin, and trichlorfon to last instar wetern spruce budworm,
Choristoneura occidentalis Freeman, were significantly altered by the presence of hostplant foliage. The pyrethroid permethrin was significantly more toxic when sprayed directly on fully exposed larvae than when first sprayed on foliage. However, all other toxicants were more toxic sprayed on foliage. A toxicologically-based method was used to assess the residual toxicities of the nine chemicals. Each chemical was applied to potted seedlings at its respective LD
90- foliage, then weathered for up to 7 days. Significant differences in toxicity were related to both insecticide and weathering interval. The toxicities of carbaryl and permethrin were least affected by weathering.
Citation
Robertson, Jacqueline L., Rappaport, Nancy L. 1979. Direct, indirect, and residual, toxicities of insecticide sprays to western spruce, budworm,
Chroistoneura occidentalis (Lepidoptera: Tortricidae). Can. Ent. 111: 1219-1226
