Masons
EOL Observer Cards
Most mason bees make nests in pre-existing cavities. They gather materials such as mud, resin, plant hairs, pebbles, or chewed leaves to line the nest, and to mold into brood cell walls and a plug at the nest opening. Look for these solitary bee nests in crevices in bark and rock, old insect holes in dead wood, abandoned wasp nests, pithy plant stems, and empty snail shells. Supplemental Notes Some tunnel-nesting mason bees, such as orchard mason bees, can be enticed to nest in aggregations in artificial nest sites such as wood blocks drilled with holes, or bundles of hollow stems or tubes. The bees can then be managed for pollination in orchards and farms. Images: 1. A wool carder bee (Anthidium manicatum) carding “wool” from lamb’s ears (Stachys byzantina) to line its nest, © Alan Phillips; 2. A male mason bee (Hoplitis spoliata) emerging from a nest, © Rob Cruickshank via Flickr; 3. Mason bees (Osmia sp.) plug the ends of their bamboo nests with mud, © poppetwithacamera via Flickr; 4. Snail shell containing brood cells of the mason bee, Osmia spinulosa, © Andreas Müller; 5. Artificial nesting blocks for mason bees, © Margriet Dogterom. Author: Jessica Rykken, PhD. Editor: Jeff Holmes, PhD. More information at: eol.org Content Licensed Under a Creative Commons License