Integrated pest management evaluation and metabolomics characterization of soybean resistant to Diceraeus melacanthus

The green-belly stink bug, Diceraeus melacanthus Dallas (Hemiptera: Pentatomidae), is an impairing pest of soybean [ Glycine max (L.) Merr.] in the Neotropics, particularly under intensified cropping systems and increasing limitations of chemical control. Host plant resistance represents a sustainable alternative within Integrated Pest Management (IPM); however, the mechanisms underlying soybean resistance to D. melacanthus and its compatibility with biological control remain poorly understood. This study characterized resistance mechanisms of the soybean cultivars BRS 539 (Block technology ®) and Fúria CE (Conkesta E3 ®). Antixenosis, antibiosis, tolerance, and compatibility with the egg parasitoid Telenomus podisi Ashmead (Hymenoptera: Scelionidae) were evaluated through behavioral, biological, and plant performance assays. In addition, untargeted metabolomics was employed to investigate constitutive and induced biochemical responses associated with D. melacanthus herbivory. BRS 539 received less herbivory and maintained plant performance under herbivory, consistent with antixenosis and tolerance-related responses. In contrast, Fúria CE negatively affected herbivore survival and reproductive parameters, indicating antibiosis, while maintaining reproductive output under infestation. Metabolomics analyses revealed contrasting defense-associated profiles between the cultivars. BRS 539 displayed a lipid-enriched constitutive metabolism associated with inducible specialized metabolites in reproductive tissues, whereas Fúria CE exhibited a predominantly stress-associated metabolic response following herbivory. Despite cultivar-dependent effects on herbivore performance, no effects were detected on parasitoid egg acceptance or emergence when T. podisi was exposed to eggs from D. melacanthus fed on either cultivar. Collectively, these findings suggest that the two soybean cultivars differ in their effects on D. melacanthus and that these differences were not associated with detectable changes in T. podisi parasitism or emergence from host eggs under the experimental conditions tested.