Combining predictions of sex ratio and mate choice models: pheromone-mediated mate choice by females in a parasitoid wasp

Abstract

Abstract In haplodiploid species, daughter production, but not son production, is sexual, requiring paternal contributions. Females may use male signals to choose a mate with better daughter-production potential, if the choice facilitates her production of adaptive sex ratios, e.g., female-biased sex ratios in systems operating under local mate competition (LMC). In the parasitoid wasp Urolepis rufipes, females preferred pheromone markings from males that had mated once versus multiply, were young rather than old, and were uninfected rather than infected when infection was low, but not when infection was high. Mates of singly-mated males had more female-biased offspring sex ratios than those of multiply-mated males, whereas there was no difference for mates of young versus old males. Thus, female preference for singly-mated males appears to provide indirect fitness benefits. A preference for young males, was not beneficial in the laboratory, but in nature young males may have mated less.