The Cape bees are unusual because they do not, unlike most animals, reproduce sexually. This means that male honeybees are not required for this particular bee population to survive. With most honeybee populations a queen lays eggs fertilized by the sperm of male drones.
Most populations of honeybees have haplodiploid sex determination. Here unfertilized eggs develop into male drones, and fertilized eggs develop into females. Female larvae that are fed of pollen, nectar, and brood food become workers, incapable of reproducing. Female larvae fed a rich diet of royal jelly, pollen, and nectar develop, into queens.
The Cape honey bee (Apis mellifera capensis) is a subspecies of the Western honey bee. The honeybees play a key role in South African agriculture by pollinating crops and producing honey in the Western Cape region of South Africa. As with other honeybee populations, the bees are at risk from pesticides and parasites (a trending topic on Twitter.)
With the bees found within the Cape of Africa, females reproduce asexually. These means they lay eggs fertilized by their own DNA, and these can develop into female worker bees. The process is called parthenogenesis. This is a natural form of reproduction in which growth and development of embryos occurs without fertilisation. The production of female offspring by parthenogenesis is referred to as thelytoky while the production of males by parthenogenesis is referred to as arrhenotoky. Whereas, when unfertilized eggs develop into both males and females, the phenomenon is called deuterotoky.
These unusual bees also seem to invade other bee nests, reproducing in this fashion and eventually taking over the nests (a form of social parasitism.
The reason for the behaviour is unknown. However, the biological mechanism has been revealed by Uppsala Universitet. Scientists have sequenced the entire genomes of a sample of Cape bees. The genome has been compared with other bee populations. The analysis has shown differences within several genes. These genes account for the ability of the bee to produce an egg that allows for reproduction without males.
In a research note, Dr. Matthew Webster, who led the project explains that study will further understating of “how genes control biological processes like cell division and behaviour.” He also adds that the study “may help us to understand the evolutionary advantage of sex.”
The research findings are published in the journal PLOS Genetics. The paper is titled “Identification of multiple loci associated with social parasitism in honeybees.”
