The effects of diploid male production on honey bee colony evolution and survival

The order Hymenoptera includes most of the eusocial species on the planet. Correlated is the fact that many of the social species within the order are haplodiploid and use complementary sex determination (CSD) to determine the sex of offspring. CSD is the mechanism by why single sex alleles within an organism result in male development (haploid) and mismatched sex alleles develop into females (diploids). Related to this is the production of diploid males: fertilized eggs with matched sex alleles which develop as male instead of female. Honey bees are no exception to this, and as their numbers continue to suffer globally and their genetic diversity lowers, the effects of diploid male production (DMP) may pose an increased risk to the survival of bee colonies. In the present study, we develop a model for diploid male production in a honey bee colony and show that with ample resources, this phenomena has little effect on a colony's health, but there is a limit to the sustainability of a colony suffering from diploid male production. We use our model to show that there were likely no great evolutionary pressures against CSD and DMP in wild honey bees as its effects on colony health in the wild would have been negligible but increased environmental hazards such as pesticides and monoculture crops increase the effects of DMP on colony health.