SURVIVAL, DEVELOPMENT AND REPRODUCTION OF COCCINELLA SEPTEMPUNCTATA L. (COLEOPTERA: COCCINELLIDAE) UNDER EFFECTS OF INSECTICIDES USED IN BEAN PLANTS

Abstract

Coccinella septempunctata L. (Coleoptera: Coccinellidae), a prevalent ladybird species, feeds on aphids and other arthropods harmful to plants. Although insecticides are commonly used to control various insects, they can harm unintended organisms through lethal and sublethal effects. This study evaluated the physiological selectivity of registered insecticides to safeguard C. septempunctata in the bean field ecosystem. Spiromesifen, deltamethrin, lambda-cyhalothrin, abamectin, chlorfenapyr, and imidacloprid were tested on eggs, third-instar larvae, pupae, and adults, with water as a control. Spiromesifen exhibited overall safety across all stages, while chlorfenapyr had minimal impact on the predator's biological features, except during the egg and adult stages. On the other hand, deltamethrin emerged as the most harmful across all stages. Lambda-cyhalothrin displayed notable toxicity to larvae and adults, similar to deltamethrin, and also affected other stages. Abamectin exhibited considerable toxicity across all developmental stages, while imidacloprid posed significant toxicity to the egg and larval stages and moderate toxicity to the adult stage. In conclusion, spiromesifen and chlorfenapyr emerged as the least toxic options for C. septempunctata and should be prioritized in Integrated Pest Management (IPM) strategies. The severe effects of deltamethrin, lambda-cyhalothrin and abamectin require further verification in field and greenhouse settings. Further studies at different concentrations and routes of exposure are suggested.