Effective population size in social hymenoptera with worker-produced males

Abstract

In the social Hymenoptera, which have haplodiploid inheritance, a proportion, ψ of the (haploid) males can be produced by the workers. It is shown that, for the special case where each laying worker produces exactly one male that survives to maturity and mates, the variance effective population size (Formula Present), where F and M are, respectively, the number of queens and males in the population. If the sex ratio is unity or female biased then Ne is reduced if there are worker-produced males, however with male biased sex ratios Ne is increased compared to its value with ψ = 0. An alternative situation, in which laying workers can each produce more than one male offspring, was investigated using computer simulations. In this case worker-produced males reduce Ne(v) regardless of sex ratio, although the effect is relatively the most weak with male biased sex ratios. A reduction in effective population size due to worker-produced males may contribute to the generally low levels of genetic variation found in the Hymenoptera. © 1989, The Genetical Society of Great Britain.