Differential sensitivity to insecticides across developmental stages of Eupelmidae: implications for Anastatus augmentative release in agroforestry IPM systems

BACKGROUND: Eupelmidae parasitic wasps are key species in agroforestry ecosystem networks that provide critical ecological services through biodiversity conservation, biological pest control, and chemical pesticide mitigation. This study evaluated the effects of five broad-spectrum insecticides (beta-cypermethrin, imidacloprid, avermectin, matrine, and chlorbenzuron) on four dominant Eupelmidae biocontrol agents (Anastatus japonicus, A. meilingensis, Mesocomys albitarsis, and M. trabalae), focusing on developmental viability, parasitic behavior, and progeny performance. RESULTS: The experimental results demonstrated a significant reduction in emergence rate across all developmental stages of both Mesocomys species following beta-cypermethrin exposure, whereas both Anastatus species maintained consistently high emergence rates exceeding 90%. The parasitism of progeny wasps was less affected by the insecticides. Beta-cypermethrin almost completely inhibited the parasitic behavior and selection of the four parasitoids, and the parasitic behavior of the four parasitoids was also affected by avermectin and imidacloprid. CONCLUSION: These results underscore Anastatus (particularly A. meilingensis) as the most field-viable candidate due to its insecticide resilience. We recommend restricting the use of beta-cypermethrin and incorporating matrine or chlorbenzuron into integrated pest management programs to conserve parasitoid efficacy in agroforest ecosystems. © 2026 Society of Chemical Industry.