Sex ratio variation in a parasitic wasp. II. Diallel cross

Abstract

The author carried out a diallel cross among three strains of Muscidifurax raptor (Hymenoptera: Pteromalidae), to measure genetic variation for sex ratio, and tested whether sex ratio may change as a consequence of selection on other life-history traits by estimating genetic covariances between sex ratio, fecundity, longevity, and development time. Most of the variation among strains could be accounted for by a maternal effect, likely caused by a microsporidian parasite that was transmitted through the West Germany strain. The inbreeding depression (the difference between inbred and outcrossed progeny) found in M. raptor implies that the evolution of a female-biased sex ratio could be affected by selection for inbreeding avoidance. -from Author