Worker-Bee Crowding Affects Brood Production, Honey Production, and Longevity of Honey Bees (Hymenoptera: Apidae)

This study measured the effects of hive volume on the productivity and growth of colonies of honey bees, Apis mellifera L., in Baton Rouge, LA. In a winter experiment, populations of 5,000, 10,000, and 15,000 bees were installed in hives to produce population densities of 150 or 550 bees per liter of hive volume (3 by 2 factorial, n = 60). More crowded bees consumed less honey (6.8 ± 1.9 mg per bee/d [mean SD] versus 12.2 ± 2.6 mg per bee/d) but produced less brood (0.34 ± 0.20 versus 0.72 -±0.31 cells per bee) and had a shorter life span than less crowded colonies. In spring, summer, and autumn, experiments were conducted with initial populations of 9,600 bees per colony. At 100, 200, 300, and 500 bees per liter (n = 32), more crowded bees produced more honey. Average honey production was -70, -17, +28, and +67 g/d for the least to most crowded bees, respectively. More crowded bees produced less brood, but the difference was less marked than in winter. A final experiment measured the effects of adding hive space that did not contain comb (n = 27). Of three treatments, colonies with five combs in a 25-liter hive produced the most honey (105 g/d), and colonies with additional space and combs (10 combs in a 47-liter hive) produced the least (29 g/d). Colonies with combless space (five combs in a 47-liter hive) were intermediate (62 g/d). The treatment with combless space produced more brood than the more crowded treatment but less than the treatment with 10 combs.