Evidence of stochastic resonance in the mating behavior of Nezara viridula (L.)

TL;DR

This study demonstrates stochastic resonance in Nezara viridula's mating behavior, showing noise can enhance signal detection and response in insect communication.

Contribution

It provides experimental evidence of stochastic resonance in insect mating behavior and models the phenomenon with a soft threshold approach.

Findings

Behavioral activation peaks at optimal noise levels.

Response probability shows non-monotonic dependence on noise.

Maximum correlation occurs near optimal noise intensity.

Abstract

We investigate the role of the noise in the mating behavior between individuals of Nezara viridula (L.), by analyzing the temporal and spectral features of the non-pulsed type female calling song emitted by single individuals. We have measured the threshold level for the signal detection, by performing experiments with the calling signal at different intensities and analyzing the insect response by directionality tests performed on a group of male individuals. By using a sub-threshold signal and an acoustic Gaussian noise source, we have investigated the insect response for different levels of noise, finding behavioral activation for suitable noise intensities. In particular, the percentage of insects which react to the sub-threshold signal, shows a non-monotonic behavior, characterized by the presence of a maximum, for increasing levels of the noise intensity. This constructive interplay between external noise and calling signal is the signature of the non-dynamical stochastic resonance phenomenon. Finally, we describe the behavioral activation statistics by a soft threshold model which shows stochastic resonance. We find that the maximum of the ensemble average of the input-output cross-correlation occurs at a value of the noise intensity very close to that for which the behavioral response has a maximum.