Stage-Specific Mortality and Developmental Effects of Synthetic Insecticides, Entomopathogenic Fungi, and Physical Barrier Agents on Chrysoperla carnea (Neuroptera: Chrysopidae): Implications for Biological Control in Avocado Orchards.

Pesticide contamination of agroecosystems poses significant risks to non-target arthropods, including natural enemies that provide essential pest regulation services. Assessing the ecotoxicological impact of reduced-risk pesticides on beneficial predators is therefore critical for both environmental safety and sustainable agriculture. This study evaluated the lethal and sublethal ecotoxicological effects of six pesticide formulations-abamectin, deltamethrin, paraffinic oil, potassium soap, and the entomopathogens Beauveria bassiana and Metarhizium anisopliae-on second-instar larvae, third-instar larvae, pupae, and adults of the lacewing Chrysoperla carnea under laboratory conditions using topical exposure. Corrected mortality was calculated using Abbott's formula. Developmental duration and adult longevity were assessed to detect sublethal effects. According to International Organisation for Biological Control classification standards, L2 larvae were the most susceptible stage, where paraffinic oil was moderately harmful, abamectin and M. anisopliae were classified as slightly harmful, and deltamethrin was harmless. In pupae, only deltamethrin was slightly harmful, while the remaining treatments were harmless. In adults, paraffinic oil was moderately harmful and abamectin was slightly harmful, whereas potassium soap and both entomopathogens were harmless. Sublethal effects included a significant prolongation of the L2 developmental stage across all treatments and reduced adult longevity following larval exposure to deltamethrin. Overall, L3 larvae and pupae were the most tolerant stages. These results identify potassium soap and the entomopathogens as the most compatible options with C. carnea, supporting their inclusion in IPM programmes for avocado orchards, while highlighting the environmental risk posed by paraffinic oil and abamectin to early larval stages and adults of this ecologically important predator.