| This dissertation addresses a major question in evolutionary biology: how do complex recognitive systems evolve? Using nestmate recognition in the highly eusocial bees as a model system, I took a two-pronged approach to answer a piece of this broad evolutionary puzzle. First, I used behavioral experiments to test for nestmate recognition in species of eusocial bees for which this has not been examined. I also investigated the identity of the chemical cues used by these species to make recognitive decisions. I found that the Neotropical stingless bee, Trigona fulviventris, displays nestmate recognition in behavioral bioassays and uses many of the same cues that the western honeybee, Apis mellifera, uses to make nestmate discriminations. In contrast, I found that the Asian honeybee species, A. cerana, A. florea, A. andreniformis and A. dorsata do not display nestmate recognition when tested with the same behavioral bioassays.; Then, because some of the cues that eusocial bees use for nestmate recognition are acquired from exposure to beeswax, I used analytical mechanical and thermal tests to examine the role of these substances in the wax. Although beeswax has been used as a material by people for myriad purposes, surprisingly little is known about its mechanical and thermal properties. Many of my results on the quantitative behavior of beeswax are here reported for the first time. I found that the fatty acids honeybees use to discriminate nestmates from non-nestmates also serve as strengtheners and stiffeners in beeswax. Additionally, using modern quantitative techniques I found that the thermal properties of bee waxes are more complex than originally reported, that melting properties vary between but not within tribes, and that the onset of melting is lower than previously published and just higher than ambient nest temperatures.; In combination, these two approaches highlight similarities and differences among species of eusocial bees to answer some of the major questions about the evolution of nestmate recognition in this group. |
