Sublethal effects of field-recommended glyphosate exposure on the predatory insect Arma chinensis: Growth inhibition and reproductive costs

Glyphosate may pose risks to non-target beneficial insects. We investigated the sublethal effects of a laboratory-simulated field-recommended concentration (3.5 g/L) of glyphosate on the predatory stink bug Arma chinensis. Although glyphosate exposure did not affect repellency or longevity, it was associated with significantly reduced weight gain and reproductive output. Integrated transcriptomic and physiological analyses revealed coordinated responses. Glyphosate exposure was associated with disruptions in central energy-sensing pathways, downregulation of lipid biosynthesis genes, and upregulation of pathways involved in lipid mobilization. Concurrently, key reproductive signaling pathways and core vitellogenin genes were suppressed, in association with delayed ovarian development and reduced reproductive fecundity. Although glyphosate altered the relative abundance of certain gut bacterial taxa, these changes were not statistically significant, and overall microbiota diversity remained unchanged. Collectively, our findings suggest that molecular-level perturbations are associated with adverse phenotypic outcomes. However, as this study was correlational, causality could not be established. Field-relevant concentrations of glyphosate may impair the fitness of this natural enemy, but this possibility requires functional validation under realistic conditions.