Comb age significantly influences the productivity of the honeybee (Apis mellifera) colony

The honeybee mainly uses the wax comb for brood rearing and food storage. Repeated brood rearing in the comb changes the wax color and cell dimensions. Therefore, we aimed to study the decline of body size of the individual bees and its impact on colony productivity in relation to comb age. Twenty colonies of hybrid Carniolan honeybees, each of 12,000 bees, were used. Combs aged 1–3 years were used as new combs, and combs aged 4–6 years as old combs. The weight of the worker, queen, drone, and royal jelly (RJ)/queen cell, storing pollen and honey, and rearing worker and drone brood were determined. The body weights of the newly emerged worker, drones, queens, and nurse and forager workers of colonies with the new combs were significantly heavier than those of the colonies with the old combs. Colonies with the new combs were significantly more active in storing pollen and honey, RJ production, and rearing workers and drones. We concluded that the body sizes of the individual bees were declined, and the productivity was decreased in the colonies with the old combs. Replace combs after three years with new others is recommended to encourage colony growth and increase productivity.