Influence of Treatment Technique on the Temperature-Toxicity Relationships of cis- and trans-Permethrin in the Cabbage Looper (Lepidoptera: Noctuidae)

Abstract

The toxicity of cis- and trans-permethrin to third instar cabbage loopers, Trichoplusia ni (Hübner), was determined at 15.6, 26.7, and 37.8°C by two treatment techniques. Whether applied topically or incorporated into the diet of the larvae, both isomers showed a negative temperature coefficient of toxicity between 15.6 and 37.8°C. However, temperature coefficients between 15.6 and 26.7°C and between 26.7 and 37.8°C varied. Data indicate that the method of application of a pyrethroid can affect its temperature-toxicity relationship.