The influence of post‐exposure temperature on the toxicity of insecticides to Ostrinia nubilalis (Lepidoptera: Crambidae)

Abstract The influence of post‐treatment temperature on the toxicities of two pyrethroids (lambda‐cyhalothrin and bifenthrin), a carbamate (methomyl) and a spinosyn (spinosad) to Ostrinia nubilalis (Hübner) larvae was evaluated in laboratory assays. From 24 to 35 °C, the toxicities of the pyrethroids decreased 9.5‐ and 13.6‐fold while spinosad toxicity decreased 3.8‐fold. The toxicity of methomyl did not change significantly. The results demonstrate that the most effective insecticide against a pest may vary with environmental conditions. In situations where comparable products from multiple insecticide classes are available, temperature should be included as a factor in the decision‐making process. Copyright © 2005 Society of Chemical Industry