Chemical communication as determinant of plant-Euglossine bee network structure: from the auto- to the macro-ecology

Abstract

Pollination is a process essential for the sexual reproduction of most of flowering plants. In approximately 90% of tropical angiosperms, pollination is facilitated by animals, mostly insects, which are oriented by chemical cues to identify flowers and access floral resources during pollination. Hence, pollination interactions constitute mutualistic relationships mediated by floral volatile organic compounds (FVs). From the perspective of community ecology, such mutualistic interactions are organized as complex networks involving plants and their pollinators. Several processes may structure interaction networks and recent studies have shown the importance of trait matching. Furthermore, the structure of plant-pollinator networks and the comprehension of the biotic and abiotic factors influencing this structure are fundamental themes in ecology. In the proposed project, we aim to characterize the interaction network composed by plants (mainly orchids) and Euglossini bees through an extensive data compilation of these interactions, including unpublished and published data, in order to test if floral chemistry is an important factor structuring the network from the Neotropics (a meta-network). In addition, at a local scale (biogeographic subdivisions of the meta-network), the same hypothesis will be tested allowing a finer, more complete and more conclusive evaluation. Finally, we aim to advance with the basic knowledge on how FV composition determines plant-pollinator interactions. Data on FV composition will be used in models as predictors of the structure of the networks. In parallel, to advance with the basic knowledge of the behavioural function of some VFs of unknown semiochemical role, we will perform field bioassays testing the attractiveness of single chemicals and their mixtures to euglossine pollinators. This project is innovative in the sense that it will use multivariate data on FV composition to analyse and predict the attributes of tropical plant-pollinator networks. We will advance further with the knowledge of how chemistry acts in plant-animal communication, from the level of individuals to the level of communities, which has not yet investigated for diverse tropical interaction networks.