What is "mason bee"

Mason \Ma"son\, n. [F. ma[,c]on, LL. macio, machio, mattio, mactio, marcio, macerio; of uncertain origin.]

1. One whose occupation is to build with stone or brick; also, one who prepares stone for building purposes.

2. A member of the fraternity of Freemasons. See Freemason.

   Mason bee (Zo["o]l.), any one of numerous species of solitary bees of the genus Osmia. They construct curious nests of hardened mud and sand.

   Mason moth (Zo["o]l.), any moth whose larva constructs an earthen cocoon under the soil.

   Mason shell (Zo["o]l.), a marine univalve shell of the genus Phorus; -- so called because it cements other shells and pebbles upon its own shell; a carrier shell.

   Mason wasp (Zo["o]l.), any wasp that constructs its nest, or brood cells, of hardened mud. The female fills the cells with insects or spiders, paralyzed by a sting, and thus provides food for its larv[ae]

n. (context zoology English) Any of the bees of the genus ''Osmia'', which have the habit of making compartments of mud in their nests.

n. any of numerous solitary bees that build nests of hardened mud and sand

Mason bee is a common name for species of bees in the genus Osmia, of the family Megachilidae. They are named from their habit of making compartments of mud in their nests, which are made in hollow reeds or holes in wood made by wood-boring insects.

Species of the genus include the orchard mason bee, Osmia lignaria, the blueberry bee, O. ribifloris, and the hornfaced bee, O. cornifrons. The former two are native to the Americas and the latter to Japan, although O. lignaria and O. cornifrons have been moved from their native ranges for commercial purposes. The red mason bee, Osmia rufa, is found across the European continent. Over 300 species are found across the Northern Hemisphere ; most occur in the temperate regions, and are active from spring through late summer.

Osmia species are usually metallic green or blue, though many are blackish. Most have black ventral scopae which are difficult to notice unless laden with pollen. They have arolia between their claws, unlike Megachile or Anthidium species.