Acoustic experience influences male and female pre- and postcopulatory behaviors in a bushcricket

Abstract

Sexual signals can provide information about the range and number of conspecifics in the social environment, and individuals may use such information to adjust their behavior accordingly. However, the extent to which both males and females adjust their behavior remains relatively unexplored. We used the chorusing bushcricket Ephippiger diurnus to test whether variation in acoustic signal experience contributes to plasticity in 1) precopulatory and 2) postcopulatory reproductive behaviors. Males produce calls containing 1–8 syllables that are repeated rhythmically within local choruses. During mating, males transfer a large spermatophore to the female, which she then consumes and removes prior to laying eggs. We reared field-collected individuals from late-instar nymphs through adulthood in one of 5 acoustic environments that varied in call syllable number: silent, low, mid, high, and mixed. We found that males 1) increased call rates in the absence of competitors, 2) increased spermatophore size in the presence of calls with a relatively low syllable number, and 3) decreased spermatophore size when exposed to calls with a variable syllable number. Females 1) became more selective as variation in potential mates increased, 2) increased egg investment when exposed to silence or calls with an average syllable number, and 3) decreased investment when exposed to calls with a relatively high syllable number, indicative of attractive males being available. The adjustments that males and females make due to acoustic experience may impact the course of sexual selection by generating feedback loops between the sexes, and in turn may contribute to divergence between populations.