Eric Mader, Pollinator Outreach Coordinator, the Xerces Society for Invertebrate Conservation 

Many current mason bee management practices are the result of previous research with the alfalfa leafcutter bee, Megachile rotundata (see chapter 7). The two groups of bees have similar life cycles, nesting requirements, and management techniques. However, while the alfalfa leafcutter bee has been managed for decades, mason beekeeping is still relatively new—having only been practiced on a commercial scale in the US since the 1990s. Earlier mason beekeeping occurred in Japan, where the native hornfaced bee (Osmia cornifrons), has been maintained as an orchard pollinator since the 1940s. Currently, 80 percent of the apples grown in Japan’s Aomori prefecture (Japan’s largest apple growing region) are pollinated by the hornfaced bee (see sidebar).

Because of their similarities, mason bees and alfalfa leafcutter bees share many of the same kinds of parasites, diseases, and other management problems. Unfortunately, most mason beekeepers are relatively inexperienced with these problems and maintain bees in conditions that would be unacceptable to experienced leafcutter producers. Individuals interested in keeping mason bees should review the leafcutter chapter of this book, noting the factors that resulted in the decline of that industry in the US.