Queen Sweat Bees Decide Role of First Brood Daughters

Amount of food provided to the offspring of sweat bees determines their role in the future, shows a new study.

Sweat bees Halictus scabiosae are eusocial insects, where they have a hierarchical structure with the queens taking the highest position, then the males and finally the workers. Despite their role in the social organization of the sweat bees, all adult bees have the ability to reproduce.

Researchers from the University of Lausanne, Switzerland, have found that the queen bees decide the role of their offspring. The first brood of the offspring is smaller than the second generation of bees given birth by the queen. The female bees belonging to the first generation become workers and help the queen in raising the next generation of bees, according to a report in BioMed Central.

For their study, the research team probed to find out if the mother bees restricted the amount of food supplied to the first generation of bees. They found that the queen bees supplied fewer amounts of pollen and nectar to the first brood of bees than the second brood. The amount of sugar given to both the broods was almost the same, suggesting that the second generation bees had more pollen.

The study carried out for nearly two years found that the first brood of bees was smaller in size compared to the second generation bees. Experts also noticed that the males belonging to the first brood were not smaller than the second generation males, which shows that the queen bees are intentionally feeding the females less food to make them take the role of workers.  

"Although it is hard to distinguish parental manipulation from resource availability and resource acquisition, which are influenced by vegetation, weather, seasonal variation, numbers of foragers and more, the fact that we were able to see that first brood female body size remained constant despite pronounced differences in weather strengthens our argument that the foundresses restrict the food of their daughters to drive them into the worker role," study author Michel Chapuisat, from University of Lausanne, said in a statement from BioMed Central.

The findings of the study are published in the open access journal in Frontiers in Zoology.