Monday, December 10, 2007 - 10:17 AM

The development of honey bee flight capacity

Jason T. Vance,, Jason B. Williams,, Michelle M. Elekonich,, and Stephen P. Roberts, University of Nevada, Las Vegas, School of Life Sciences, 4505 Maryland Pkwy, Las Vegas, NV

During behavioral development, honey bees undergo numerous physiological changes, including a large increase in aerobic capacity, presumably to support the intense flight demands of foraging behavior. In this study we addressed whether kinematic and aerodynamic performance/capacity increases as honey bees age and transition from hive bees to foragers. The flight performance of age-matched hive bees and foragers was determined by identifying the least-dense gas that allowed for hovering flight, using six variable-density gas mixtures ranging from air (21% O2, 79% N2; 1.21 kg m-3) to heliox (21% O2, 79% He; 0.41 kg m-3). Wingbeat frequency and wing stroke amplitude were determined from high-speed (4347 fps) digital video recordings of these trials. Typical honey bee foragers (age > 14 days) were able to hover in pure heliox by increasing wing stroke amplitude and maintaining a relatively constant wingbeat frequency, which greatly increased wingtip velocity and aerodynamic lift. In response to hypodense gas, young foragers (age < 14 days) and hive bees increased stroke amplitude but decreased wingbeat frequency, which only moderately increased wingtip velocity. Differences in body mass may explain why young foragers were capable of hovering in lower density gases than hive bees, despite similar flight kinematics at maximal capacity, and why hive bees required 15% greater stroke amplitude than young foragers during hovering in air. These results suggest that the increased flight performance of foragers is a function of both reduced body mass and physiological/biomechanical enhancement of kinematics relative to younger bees.

Species 1: Hymenoptera Apidae Apis mellifera (honey bee)