Parental relatedness and parasitoid sex ratios under local mate competition

Sex ratio theory predicts that, under local mate competition, a more female-biased offspring sex will be produced by females when their relatedness to mates is closer. We assess how the sexual composition of broods responds mother–mate using Goniozus legneri Gordh (Hymenoptera: Bethylidae), parasitoid wasp that has biased ratios due competition. Relatedness was varied providing virgin with either sibling, non-sibling from same strain, strain geographically similar origin or distant origin. The among mothers had mated sibling same-strain male were and than males different strain. Brood variances higher after mating different-strain males. Previous evaluations responses have not found patterns predicted, possibly because species investigated can control progeny but cannot discriminate kin. In contrast, female G. appear possess both these abilities appears respond in qualitative agreement theoretical predictions.