Wall Mason Bee

The wall mason bee is a medium sized bee which is mostly black in colour, with ginger hair on top of the abdomen. They live in areas of unimproved grassland where they feed on the pollen of the common bird's-foot trefoil and they take flight from May to July. They nest in crevices in drystone walls, rock faces, and standing deadwood and have a single-brood. 

They work alone, the female lays the eggs, as well as goes out to collect nectar for food. Like other solitary bees, they only live for approximately 10 weeks. Once the eggs are in the nest and everything is sealed up their job is done. They collect pollen and nectar for energy and the nests, but there is no need to create stores of food due to their short lifespan.

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Mason bees don’t fly far for food and only travel about 300m of their nest. They have to visit approximately 1875 flowers for a single larva.

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It is under threat by the overgrazing of meadows where bird's-foot trefoil grows, poor woodland management as sunny glades and woodland clearings are essential habitats for wildflowers, and human activity such as the manual removal of drystone walls and standing deadwood also removes essential sites for their nests.