Eur. Phys. J. B 65, 453-458 (2008)
https://doi.org/10.1140/epjb/e2008-00333-4

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

¹ Dipartimento di Fisica e Tecnologie Relative, Group of Interdisciplinary Physics (URL: http://gip.dft.unipa.it) , Università di Palermo, Viale delle Scienze pad. 18, 90128 Palermo, Italy
² Mark Kac Complex Systems Research Center and Marian Smoluchowski Institute of Physics, Jagellonian University, ul. Reymonta 4, 30-059 Kraków, Poland
³ Dipartimento di Scienze Entomologiche, Fitopatologiche, Microbiologiche agrarie e Zootecniche, Università di Palermo, Viale delle Scienze pad. 5, 90128 Palermo, Italy

Corresponding author: ^a spezias@gip.dft.unipa.it

Received: 18 May 2008
Revised: 7 July 2008
Published online: 22 August 2008

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.