Male Responses to Conspecific Advertisement Signals in the Field Cricket Gryllus rubens (Orthoptera: Gryllidae)

Yikweon Jang,Matjaz Perc

doi:10.1371/journal.pone.0016063

Abstract

In many species males aggregate and produce long-range advertisement signals to attract conspecific females. The majority of the receivers of these signals are probably other males most of the time, and male responses to competitors' signals can structure the spatial and temporal organization of the breeding aggregation and affect male mating tactics. I quantified male responses to a conspecific advertisement stimulus repeatedly over three age classes in Gryllus rubens (Orthoptera: Gryllidae) in order to estimate the type and frequency of male responses to the broadcast stimulus and to determine the factors affecting them. Factors tested included body size, wing dimorphism, age, and intensity of the broadcast stimulus. Overall, males employed acoustic response more often than positive phonotactic response. As males aged, the frequency of positive phonotactic response decreased but that of the acoustic response increased. That is, males may use positive phonotaxis in the early stages of their adult lives, possibly to find suitable calling sites or parasitize calling males, and then later in life switch to acoustic responses in response to conspecific advertisement signals. Males with smaller body size more frequently exhibited acoustic responses. This study suggests that individual variation, more than any factors measured, is critical for age-dependent male responses to conspecific advertisement signals.

Highlights

Males of many acoustic species such as insects and anurans may form breeding aggregations and produce advertisement signals to attract females
Ethical treatment of animals Ethical approval was not required for the field cricket Gryllus rubens, the subject in this study, because G. rubens is not listed as an endangered species
The primary response to the conspecific advertisement signals switched from positive phonotaxis to song production

Summary

Introduction

Males of many acoustic species such as insects and anurans may form breeding aggregations and produce advertisement signals to attract females. When neighboring males in close proximity interact with each other acoustically, chorus structure [4,5,6] and spatial distance between adjacent signalers [7,8,9] are mediated by the response to neighbors’ signals. In addition to the structure of breeding aggregations, male responses to conspecific advertisement signals affect male mating tactics. There is evidence that the choice between alternative mating tactics typically employed by a singing insect or anuran may depend on characteristics of the conspecific advertisement signals [14]. Male response to conspecific advertisement signals can structure the spatial and temporal organization of the breeding aggregation and determine male mating tactics

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