Female remating and the intensity of female choice in black-horned tree crickets, Oecanthus nigricornis

Repeated mating by females of many species occurs at frequenciesin excess of those needed to acquire additional sperm for fertilizingova. I tested three alternative hypotheses for the rate of rematingby females of the courtship-feeding tree cricket, Oecanthusnigricornis Walker, by manipulating diet quality and courtshipfeeding and measuring the time to remating by the female inrelation to four aspects of male phenotype (age, condition,fluctuating asymmetry, and size). First, in courtship-feedingspecies, remating may be due to selection to increase the amountof nutritional resources provided by males, with nutrient-deprivedfemales remating more quickly. Second, remating may functionas a mechanism of postcopulatory mate choice, with females rematingquickly when the quality of a previous mate is low. Third, quicknessof remating may be the consequence of precopulatory mate choiceprior to future matings, with females remating more quicklywith high-quality males, regardless of the quality of priormates. Females on a low-quality diet remated quickly, did notvary remating speed with the phenotype of their first mate,and did not differentially reject prospective second mates withdifferent phenotypes. In contrast, both the degree of coyness(measured as the frequency of mate rejection) and the intensityof female choice (measured as the size differential betweenaccepted and rejected mates) increased with diet quality. Theseresults support both the material-benefits and the precopulatorymate-choice hypotheses for remating speed of female tree crickets.There was mixed support for the postcopulatory choice hypothesis:females on the high-quality diet remated more slowly after firstmating with relatively large males, in support of the postcopulatorychoice hypothesis; however, the remating interval of femaleson the high-quality diet decreased with the condition of thefirst mate, opposite to the prediction of the postcopulatorychoice hypothesis