chard pollinator. Many thousands of mason bee nesting blocks are sold each year in the United States, along with hundreds of thousands of blue orchard bees. This interest has greatly raised public awareness about the importance of pollinators; however, it is important to remember that raising large numbers of a single species (bee-ranching) is a different objective than the conservation of diverse species of wild pollinators.
As mason beekeeping has increased in popularity, important questions are being asked about the risks associated with the nationwide shipment of blue orchard bees by commercial producers. In fact, there are two distinct subspecies of the blue orchard bee: Osmia lignaria propinqua in western North America and Osmia lignaria lignaria in the east. The species is rare in the Great Plains region, although some intermediate specimens have been collected.
Most commercial producers of the blue orchard bee are located in the Pacific Northwest, where they rear the locally native western subspecies . Unfortunately, the bees these producers raise are then marketed nationwide, resulting in the frequent shipment of locally non-native bees to the eastern United States. The potential ecological consequences of the western blue orchard bee hybridizing with its eastern subspecies are unknown. Similarly, these shipments have the potential to introduce locally non-native parasites and diseases. For the consumer, there is another significant drawback. The western bees may not develop in sync with local conditions, resulting in poor establishment and poor performance as pollinators. The net result is that people purchasing blue orchard bees over the Internet or through garden catalogs may be doing more to harm their local pollinator populations than to help them – and not be getting the pollination they paid for.
This is a family of bees that are often referred to collectively as plasterer bees, due to the method of smoothing the walls of their nest cells with secretions applied with their mouthparts; these secret