Honeybee egg size is linked to land use and predicts worker foraging performance

Abstract

Humans have changed the nutritional landscape available to bees, increasing the risk of nutritional stress and health challenges. Honey bee (Apis mellifera) queens are known to increase worker egg size during times of nutritional stress, suggesting that land use may affect honey bee egg size. Furthermore, it is currently unknown whether a change in egg size has downstream consequences for adult workers. We tested if egg size varies between rural and urban areas in southwest England. Egg size in rural areas was significantly larger, indicating nutritional differences between the two land use types. Increased colony weight, suggesting increased food stores, were associated with smaller egg sizes. Experimentally inducing queens to lay larger eggs by colony splitting and then using radio-frequency identification (RFID) technology, we found that bees from larger eggs performed 23.8% more foraging trips. However, there was no significant effect of egg size on bee body size or lifespan. These findings suggest that egg size may influence foraging activity in honey bee colonies without impacting other important adult worker traits. Future research should address the mechanisms linking egg size to worker behaviour under varying environmental conditions.