Ecological Impacts of Introduced Honey Bees

Honey bees (Apis mellifera L.), native to Eurasia and Africa, have been introduced to most of the rest of the world. Many plant species are used by introduced honey bees, which suggests a high potential for disturbance of native plant/pollinator relationships. Few species are used intensively, however, thus decreasing the opportunity for disturbance. Pollination studies show that honey bees are effective pollinators of some native plants and less effective pollinators of others; they also reduce floral resources in some species with little or no pollination. Data are insufficient to show whether honey bee foraging on native plants significantly alters pollen and gene flow, but unusual foraging behavior by honey bees is not evident compared to many other pollinators. Honey bees do not physically damage plants; they are also unlikely to increase hybridization of native flora. Pollination by honey bees probably contributes little to the success of most weeds. Experiments have not shown competition for nesting sites between honey bees and native fauna. The presence of honey bees, however, alters the foraging behavior and abundance of some native fauna on flowers, but no studies have shown detrimental impacts of honey bees on population abundances of any native animals or plants. Anecdotal and quantitative reports of increased honey bee abundances on flowers compared with native fauna are often confounded with habitat changes induced by man.