Effect of population size on brood production, worker survival and honey gain in colonies of honeybees
John R. Harbo
The effect of population size on brood production, worker survival and gain or loss of honey was studied in colonies of honeybees (Apis mellifera) in Louisiana, USA. About 11 kg of bees were caged, stored for two days and subdivided into five populations numbering 2300, 4500, 9000, 17 000 and 35 000 bees. Each colony was started with a laying queen, no brood, and 230 bees per 1000 cm3 of hive space. The test ended 19 days after queen release, just before adult bees began to emerge. The test was conducted 10 times (two replicates being used in each of February, April, June, August and October). The two largest populations produced more honey per bee and in dearth times and winter consumed less honey per bee. Colonies of 4500 bees produced the most brood per bee; as population increased above that number brood production per bee decreased. However, during summer dearth, the colonies of 9000 bees produced the most brood per bee. Overall, the optimal colony size was 9000 bees; the rate of weight gain in colonies of this size was nearer to that of the two largest populations and the rate of brood production was nearer to that of the two smaller colonies.
brood production, worker survival, population size, honey gain, honeybees,