Sex ratio variation in a parasitic wasp. I. Reaction norms

Abstract

To understand genetic and phenotypic constraints on the sex ratio in a parasitic wasp that attack fly pupae, the author carried out a laboratory study of sex ratio variability in five strains of Muscidifurax raptor (Hymenoptera: Pteromalidae). Sex ratio variability among strains is constrained by the correlation between sex ratio and fecundity. Strains display similar facultative shifts in sex ratio as female density increases because sex ratio shifts are insensitive to differing levels of superparasitism. -from Author