Double stochastic resonance in stink bug sexual communication

Stochastic resonance (SR) is a phenomenon where noise enhances the detection of weak signals in nonlinear systems. In this study, we investigate the role of environmental noise in facilitating acoustic communication during mating in the southern green stink bug, Nezara viridula (L.), a globally distributed and highly polyphagous pest species. Using behavioral experiments and the source-direction movement (SDM) ratio as a metric, we demonstrate that environmental noise can significantly improve signal recognition between individuals of opposite sex. Notably, the SDM ratio exhibits a nonmonotonic response with two distinct peaks, indicating the presence of a double behavioral stochastic resonance -a phenomenon previously predicted theoretically but not observed in biological systems. The noise intensity levels used in laboratory experiments closely match those recorded in natural habitats, reinforcing the ecological relevance of our findings. These results suggest that environmental noise may play a constructive role in enhancing mating communication in N. viridula, offering new insights into pest control strategies based on acoustic signaling.