Ecology of Urban Bees: Preference for Native Plants in the Green Spaces of Quito

Across the Andes, bees are a heavily understudied group of insects, and despite it being seemingly counterintuitive, urban ecosystems are home to some of the least studied bees in the region. This, combined with the largely modified plant communities that characterize South American urban green spaces, where European and North American flora often rivals in abundance and richness with that of native plants, makes it so Andean cities like Quito, Ecuador, are perfect for studying both the ecology of bee pollinators, as well as the impact that exotic species have on native bees. We reviewed the reported diversity and interactions inside citizen science platform iNaturalist and in local entomological collections, and we also conducted direct observations on 5 native and 3 exotic plant species inside a city park during a four-month period, of which 6 species produced sufficient flowering for analysis, all in order to answer: 1) What is the diversity and spatial distribution of bee species and their plant associations across the urban green spaces of Quito? 2) Do native bee species show stronger preferences for native versus exotic flowering plants, and which plant species are most important for urban pollinators? We were able to identify 31 morphospecies belonging to five bee families, of which only one species was exotic. When excluding the exotic Apis mellifera , all four native bee families showed preference towards native flowering plants, although most bees were also shown to be polylectic, capable of visiting other flowers whenever their preferred food source was not available. We determined that abundance and richness of native plants held the highest correlation with native bee diversity, and we also identified Dalea coerula, Bidens andicola and Lupinus pubescens as the most important plants for urban pollinators inside the city of Quito. Overall, the implementation of native plant patches inside urban greenspaces is a decisive factor for bee conservancy in urban ecosystems of South America.