Reviewing the use of bee trap nests for the study of interaction networks in agroecosystems: insights from its use in olive farms

The analysis of interaction networks can contribute to our understanding of community ecology with more detailed, mechanistic and potentially predictive information than studies focused only on abundance of individuals or species richness. The use of interaction networks has spread significantly in the last decade. However, studies using this community analysis tool from an applied perspective are still scarce, especially in agroecology. Its use is being probably limited by the difficulty and effort associated to sampling interactions between species. Nonetheless, there are some tools that can ease this task, like bee trap nests or bee hotels, traditionally used to increase the abundance of wild pollinators in agricultural environments. This review aims to show how bee hotels can be used for more purposes beyond the management or restoration of above ground cavity nesting bee communities and the pollination function in agroecosystems. Here we show that they are also useful as a tool to sample interaction networks and thus provide answers to a broad array of important questions in ecology, agroecology, or more theoretical fields. In this review, we use a number of examples to show, illustrate and inspire the application of bee hotels. We emphasize our current work in Andalusian olive orchards, where we investigate how to restore the function and diversity of pollinators and pest natural enemies.