not live long and are not as effective as pollinators. Competing flowers such as dandelions should be mowed as soon as the fruit begins to bloom.
Developing large populations of the bees may be a slow process under orchard conditions; the short duration of bloom does not allow the bees to accomplish maximum reproduction. The orchard mason bee also has a tendency to fly away rather than using or reusing nests in the near vicinity. However, relatively large populations have been developed in 2 or 3 years in urban situations. Once established, orchard bees will nest in containers filled with large-diameter drinking straws or paper tubes folded in half.
Orchard Mason Bee, Osmia lignaria. This is a megachilid bee that as do other mason bee makes nests in reeds and natural holes, creating individual cells for their brood that are separated by mud dividers. They are unlike carpenter bees in that they cannot drill holes in wood. O. lignaria is a common species used for early spring fruit bloom in Japan, Canada, and the United States, though a number of species of other Osmia are also cultured for use in pollination.
Orchard Mason Bee. Image Courtesy Red58bill.
The bees begin to emerge from their cocoons in the spring when the daytime temperature reaches 14°C (57°F). The males emerge first. They remain near the nesting site and wait for the females to begin their emergence, which can be several days to weeks depending on the number of days of warm weather. The first thing the females do is mate. A female will typically mate once, maybe twice. She will be absent from the nesting site for several days while she feeds and waits for her ovaries to fully mature.
When a female is ready, she seeks out a suitable nest. O. lignaria females like to nest in narrow holes or tubes, though they have been found to nest inside cedar shakes and even keyholes. Beekeepers put out pre-made nesting materials to entice the females to stay close to the orchard. Rain, wind, and free-release (the practice of putting loose cocoons out rather than 