Flower Visitation by Bees, Wasps and Ants: Revealing How a Community of Flower-Visitors Establish Interaction Networks in a Botanical Garden

Abstract

The Hymnoptera order includes several flower-visiting insects (e.g. ants, bees, and wasps) and the coexistence of many different species in the same community can generate interspecific competition. Notwithstanding shared communities, research which evaluates how these taxonomic groups influence a whole community of flower-visiting Hymenoptera is lacking. Moreover, abiotic factors can also impact these floral visits, because each organism responds differently to climatic variations. The goal of this study is to evaluate abiotic factors, specifically relative air humidity and air temperature, which may be able to impact the number and the frequency of interactions between hymenopterans and flowers and to assess the composition and niche organization, by making use of interaction networks, of the entire community of flower-visiting Hymenoptera at the botanical garden of the Universidade Federal Rural do Rio de Janeiro. For the duration of a year, we took samples in that botanical garden, compartmentalizing the collections temporally in accordance with the time of the insects’ shift (morning or afternoon). We observed a positive influence of air temperature on the number of ant interactions and visits. It is also possible to observe that most of these interaction networks exhibited a nested and non-modular pattern and an average level of network specialization. In addition, bees stood out as the species with the highest frequency of visits and with the most generalist behavior. This study demonstrates how a botanical garden can sustain a diverse community of floral visiting Hymenoptera in an urban environment and why it consists in an important tool for biodiversity conservation.