Linking biological diversity and chemical diversity

Background/Question/Methods
The highly social stingless bees (Apidae: Meliponini) are important pollinators in tropical ecosystems. Besides pollen and nectar they also collect large amounts of plant resins which they use for nest construction and defense. They further transfer resin-derived terpenes to their body surfaces, thereby increasing the diversity of their chemical profiles. We observed resin collection by stingless bees at trees and colony entrances in Borneo, to investigate whether bees collected resin from many different or only few specific trees and whether different bee species differed in or shared their preferred resin trees.

Results/Conclusions
At our field site, all stingless bee species collected resin from several tree species, particularly from trees of the resinous dipterocarp family. All colonies collected a large variety of resins, suggesting that stingless bees visit several tree species rather than just a few adjacent resin wounds. Analysis of network-level specialization revealed that stingless bees are highly generalist resin collectors with no specific preferences for specific tree species but a variety of resin sources visited. Although stingless bees collect a large variety of resins, they only transfer a subset of terpenes derived from these resins to their body surface. Some species even exclude whole classes of terpenes, thereby increasing chemical differences between species and revealing a hitherto unknown ability of bees to filter terpenes derived from resins and embed them in their chemical profiles.

Talk at the 95th Annual Meeting of the Ecological Society of America (ESA)