The role of fatty acids in the mechanical properties of beeswax

Beeswax is a mixture of many organic compounds, including hydrocarbons, wax esters, and fatty acids. Because fatty acids in beeswax also serve as social signals, we explored the functional significance of the fatty acids. The removal of the fatty acids from beeswax results in diminished yield stress, resilience, stiffness, and proportional limit stress of beeswax samples. Addition of stearic acid to beeswax enhances all of these properties except resilience. Artificial wax mixtures show a positive correlation between the amount of stearic acid in the wax mixture and yield stress. Unsaturated fatty acids found in beeswax behave similarly, with respect to their effects on the mechanical properties of artificial wax mixtures. Fatty acid concentration showed significant variation among colonies, particularly among the unsat-urated fatty acids. We interpret these findings with respect to the mechanical properties of beeswax and the role of fatty acids in communication among bees.