Abstract The compatibility between insecticides and biological control agents is essential for the success of Integrated Pest Management (IPM) strategies. This study evaluated the lethal, sublethal, and transgenerational effects of 5 insecticides—malathion, bifenthrin, beta-cyfluthrin, diflubenzuron, and tebufenozide—on Trichogramma atopovirilia Oatman & Platner, 1983 (Hymenoptera: Trichogrammatidae), a parasitoid and potential biological control agent of Gymnandrosoma aurantianum Lima, 1927 (Lepidoptera: Tortricidae) in citrus orchards. The results showed that malathion, bifenthrin, and beta-cyfluthrin significantly reduced parasitism, emergence, and adult longevity. These insecticides were classified as harmful (Class 4), moderately harmful (Class 3), and slightly harmful (Class 2), respectively, according to the IOBC/WPRS guidelines. In contrast, diflubenzuron and tebufenozide were classified as harmless (Class 1), demonstrating minimal adverse effects on biological parameters and exhibiting low persistence under simulated field conditions. Transgenerational evaluations indicated that while emergence and sex ratio remained unaffected, longevity was reduced in certain treatments. These results highlight the importance of selecting insecticides that are compatible with natural enemies in IPM programmes, and suggest that insect growth regulators are a safe and effective alternative to conventional insecticides for conserving T. atopovirilia in citrus agroecosystems.
Wappler et al. (Mon,) studied this question.