SUPERPARASITISM AND SEX-RATIO IN THE SOLITARY PARASITOID EPIDINOCARSIS-LOPEZI

Highly variable sex ratios are found in the solitary parasitoid Epidinocarsis lopezi, both in the field and in a mass-rearing situation. Superparasitism is one of a number of factors which can influence sex ratios in parasitoid Hymenoptera. We show that superparasitism in E. lopezi is common in the field. Sex allocation decisions when parasitizing unparasitized hosts are not different from those with parasitized hosts; neither does differential mortality occur between the sexes in superparasitized hosts. Therefore superparasitism does not contribute to the variable sex ratio of E. lopezi. Both the occurrence of superparasitism and the sex produced when ovipositing are shown to be functional for E. lopezi.