Plant Resins—Their Role for Plants and Use by Stingless Bees

This chapter summarizes the ecological role of resin for plants and highlights differences in function and chemistry of different resin types, their use by stingless bees, and coevolution. Unlike pollen and nectar, resins are mostly used for defense against natural enemies, mainly herbivores and granivores. However, opportunistic resin use by stingless bees can result in mutualisms, like pollination or seed dispersal. Thus, resin can represent complex trade-offs and consists of species-specific mixtures of various chemical compounds, mostly terpenoids and phenolics. These herbivore deterrents may be toxic to many organisms including insects and flower visitors. To make use of resin, bees have adapted their physiology and behavior to cope with resin toxicity, likely in ways similar to adaptations concerning pollen and nectar deterrent chemicals. While not all Apis species use resin, all stingless bees use resins for nest construction and defense. Some species also incorporate compounds from resin in their cuticular surface profiles. Despite such a fascinating interaction between resin-producing plants and bees, we still know very little about resin and the chemical ecology of stingless bees.