Floral resource use by the non-native cavity-nesting bee, Osmia taurus, in Morristown National Historical Park, New Jersey

Several human activities, including the reduction of foraging habitats, increased pesticide use and the introduction of new emerging pests and diseases may have contributed to the drastic decline in Apis mellifera populations. As many of the plants in forests and agricultural systems are bee pollinated, there have been increased efforts to find other species of bees that could be managed as alternative pollinators. The USDA introduced Osmia cornifrons, a cavity-nesting orchard bee, in 1977 from Japan to serve as a possible alternative pollinator. After the introduction of O. cornifrons, there have been instances where another species, Osmia taurus has been observed in the eastern continental U.S. Due to similar physical and habitual characteristics compared with O. cornifrons, it is possible that O. taurus was accidently introduced to the United States when O. cornifrons were intentionally brought from abroad. Conservation biologists are concerned that these non-native bees, O. taurus, are competing with the native Osmia species for floral and nesting resources. This study seeks to understand the floral resources that are being used by non-native bee, Osmia taurus, in New Jersey, part of its introduced range. We predicted that since species in the Osmia genus are generalists, O. taurus will use a variety of floral resources to provision their offspring in the nests. However, although Osmia are generalists, we predicted that they would have some floral preferences regardless of floral abundance in individual sites. In 2013, we analyzed the pollen samples in nest boxes placed in Morristown National Historical Park, New Jersey in spring of 2012. We found that results suggest O. taurus s prefers few specific floral resources, as several pollen types are found consistently throughout the sampling sites across several forest types in the park.