Influence of temperature on the toxicity and stability of insecticide resistance against Spodoptera littoralis (Lepidoptera: Noctuidae)

Abstract Background Spodoptera littoralis Boisad. (Lepidoptera: Noctuidae) is an important pest causing significant losses to agricultural crops worldwide. Management practices for this insect pest rely on insecticides applications throughout the entire season over wide ranging temperature. However, studies involving the development of resistance in S. littoralis against these insecticides at different temperatures are limited. Methods Using leaf-dipping bioassay technique, the effect of temperature (range, 15–30 °C) on the toxicity of spinosad, lambda-cyhalothrin and methomyl, and resistance development was evaluated in larvae S. littoralis. Results Spinosad, lambda-cyhalothrin and methomyl exhibited increased toxicity with increasing temperature from 15 to 30 °C. The results indicated a successive decrease in insecticide resistance at the temperatures of 15, 20, 25 and 30 °C from 1st to 12th generations of S. littoralis to spinosad, lambda-cyhalothrin and methomyl. Conclusions This study suggests that spinosad, lambda-cyhalothrin, and methomyl can be included in the management of S. littoralis.