Free Access
Volume 40, Number 5, September-October 2009
Page(s) 585 - 594
Published online 06 June 2009
Apidologie 40 (2009) 585-594
DOI: 10.1051/apido/2009035

The role of fatty acids in the mechanical properties of beeswax

Robert Buchwald1, Michael D. Breed2, Louis Bjostad3, Bruce E. Hibbard4 and Alan R. Greenberg5

1  Department of Integrative Biology, 3060 VLSB, University of California, Berkeley, CA, 94708, USA
2  Department of Ecology and Evolutionary Biology, EBIO, CB 334, University of Colorado, Boulder, CO, 80309-0334, USA
3  Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO, 80523, USA
4  USDA-ARS, Curtis Hall, University Of Missouri Columbia, MO, 65211-7020, USA
5  Department of Mechanical Engineering, UCB 427 University of Colorado, Boulder, CO, 80309-0427, USA

Received 3 July 2008 – Revised 1 December 2008 – Accepted 18 March 2009 - Published online 6 June 2009

Abstract - 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 unsaturated fatty acids. We interpret these findings with respect to the mechanical properties of beeswax and the role of fatty acids in communication among bees.

Key words: Apis mellifera / wax / fatty acid / yield stress / stiffness

© INRA, DIB-AGIB, EDP Sciences 2009