Sexual signal loss, pleiotropy, and maintenance of a male reproductive polymorphism in crickets

<p>Pleiotropy between male signals and female preferences can facilitate evolution of sexual communication by maintaining coordination between the sexes. Alternatively, it can favor variation in the mating system, such as a reproductive polymorphism. It is unknown how common either of these scenarios are in nature. In Pacific field crickets (<i>Teleogryllus oceanicus</i>) on Kauai, Hawaii, a mutation (<i>flatwing</i>) that segregates as a single locus is responsible for the rapid loss of song production in males. We used outbred cricket colonies fixed for male wing morph to investigate whether homozygous <i>flatwing</i> and <i>normal-wing</i> (wild-type) females differ in responsiveness to male calling song and propensity to mate when paired with either a <i>flatwing</i> or <i>normal-wing</i> male in the presence or absence of courtship song. <i>Flatwing</i> females were less likely to mount a male than <i>normal-wing</i> females. Females of both genotypes showed a preference for <i>normal-wing</i> males and were more likely to mate in the presence of courtship song; n<i>ormal-wing </i>females<i> </i>were<i> </i>particularly likely to mate with song. Our results show that negative pleiotropy between obligate male silence and female mating behavior can constrain the evolution of sexual signal loss and contribute to the maintenance of a male reproductive polymorphism in the wild. </p>