We were entertained, enthralled and captivated by the size of dried grass pieces she wove together. A couple of weeks later I saw another bee in the same marble bed building another nest.

Usually in the autumn I 'tidy' this bed, pulling out weeds, cleaning the marbles etc, but now it will remain as it is for the Mason Bees to build as many homes as they wish. They are very welcome in our forest garden.

Mason Bee

Mason Bee is a term commonly used for species of bees in the genus Osmia. These fascinating and important bees will nest in almost any cavity which they will if necessary modify with earth or other materials to suit their requirements. This could be an existing hole in wood, a fissure in a wall or tree, hollow stems or canes and some species even use empty snail shells. In the case of empty snail shells, once the nest is provisioned with eggs and nutrition it is sealed with grit and soil before being carefully covered by the female with pieces of grass presumably to protect it.

She will sometimes position the shell by moving it around a little. Osmia aurulenta, Osmia bicolour and Osmia spinulosa are three species that typically use empty snail shells. Pollen is collected on a pollen brush of hairs beneath the females’ abdomen. 

Mason bees usually live for a year, although humans only see the active adult stage, which lasts about 3 to 6 weeks. Mason bees only travel 30 - 100 meters from their nest, about the length of a football field.

The benefit of Mason Bees is that they are excellent pollinators, 120 times more effective than honey bees or bumble bees. This is because those bees have a colony to support and carry most of the pollen they collect back to the hive. Mason Bees do not have a hive so all of the pollen they collect stays with them.

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