Competition between honeybees (Apis mellifera) and native solitary bees in the Mediterranean region of Israel-implications for conservation

The hypothesis that honeybees (Apis mellifera) compete for floral resources with native bees was studied mainly in areas outside the original range of the honeybees, i.e., where they are introduced. We studied the effect of honeybees on the foraging behavior of native solitary bees in Israel, within the natural distribution range of the honeybee, by manipulating the presence and absence of beehives in the study sites: Ramat Hanadiv Park and Carmel National Park. We examined the possible degree of competition between honeybees and native solitary bees by observing their foraging on focal nectariferous plants. Temporal introduction of hives increased the visitation frequencies of honeybees to our focal plants and decreased the overall average visitation frequencies of native solitary bees. However, the effect of honeybees varied among native bee species, focal plants, and years. In some cases, honeybees had a negative effect on visitation rates of the other bees, while in other cases we did not find such an effect. The other bees also did not shift to forage on other flowering plants, and did not change their temporal activity pattern as a response to increased foraging by honeybees. The results provide partial evidence for behavioral competition between honeybees and native bees. For this reason, we recommend prohibiting introduction of beehives to all nature reserves in Israel, as a precaution aimed at protecting the native bee fauna. This may help conserve their contribution to biodiversity and pollination of common and rare native plants as well as crops.