The Relationship of Apis mellifera with Exotic and Native Plants in Boulder County, Colorado

Since honeybees (Apis mellifera) were introduced to North America in the 1600’s, their influence has been profound and widespread. As pollinators, honeybees are extremely valuable economically and are vital to crop pollination. However, their presence has affected native ecosystems, including the plains ecosystem in Colorado. Using recruitment and other unique foraging characteristics, honeybees may be out-competing native pollinators for nectar and pollen resources. Our study was designed to determine if A. mellifera has a preference for exotic or native plants. We observed patches of exotic plants and patches of native plants and recorded the type of bee (exotic or native) that visited each flowering head. We also examined data from Kearns and Oliveras (unpublished), which illustrates that invasive plant species are also popular with native bees, and may draw vital pollinators away from native plants. Our results indicate that honeybees prefer to visit exotic invasive plant species to native plants. Consequently, honeybees may contribute to the spread of exotic plant species and the decline of native plant species, reducing biodiversity. Thus, native plants are doubly jeopardized. The invasion of exotic flora and fauna into native ecosystems on the plains of Colorado is part of a worldwide phenomenon of species invasion, and researchers must continue to investigate interspecies relationships to minimize the potential negative effects of invasive species.