Spring Mason Bees
Blue Orchard Bee, Osmia lignaria (western U.S. only*)
The blue orchard bee is a docile bee native to North America. Adult bees emerge from their cocoons in the spring when fruit trees and many of our native shrubs and herbs are in bloom. These highly efficient pollinators increase fruit production as well as improve the overall health of their ecosystems. This mason bee uses mud to build nest partitions and protect their young from invading pests. They are fun to watch throughout the spring and are an important member of western ecosystems.
(*This bee species is available in the following states: Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming.)
Horn-faced Bee, Osmia cornifrons (midwestern and eastern U.S. only*)Horn-faced bees are found throughout the midwestern and eastern United States, and are used around the world for fruit tree pollination. Similar to blue orchard bees, adult horn-faced bees are also active during spring when many trees, shrubs, and herbs are in bloom. In addition to mud, this mason bee often also uses leaf pulp to construct their nest partitions. Horn-faced bees are better suited to humid environments than are blue orchard bees, and can also tolerate cold climates.
(*This bee species is available in all U.S. states EXCEPT: Alaska, Alabama, Arizona, California, Colorado, Florida, Georgia, Hawaii, Idaho, Louisiana, Mississippi, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming.)
Summer Leafcutter Bees
Leafcutter Bee, Megachile rotundata (Nationwide*)
Leafcutter bees are found across North America and are used around the world for alfalfa pollination. Honey bees do not efficiently pollinate alfalfa due to a spring-loaded pistil mechanism in the alfalfa flower which they avoid. The small leafcutter bee effectively pollinates by “tripping” the pistil, and is responsible for creating the majority of feed for pigs and dairy cows. They are an equally gentle generalist bee that will visit a majority of types of flowers in your backyard during their flying months of July and August, including your flowering vegetable garden. As their name suggests, leafcutter bees use leaf pieces, which they cut using their mouth-parts, to construct their nests.
(*This bee species is available in all U.S. states EXCEPT: Alaska and Hawaii)