Besides honey bees and bumblebees there are some 300 other species of bees in the Netherlands. These are solitary bees. Of the solitary bees 70% breed in the soil and 30% in cracks and holes.
As the name says, these bees do not live in social groups but alone. They do, however, often nest in congregations (gregarian behaviour).
In 2007 solitary bees received a lot of scientific attention; showing that the decline of these bees is associated with the decline of plant diversity. Bees@wur searches for possibilities to help these bees by giving them a place within agricultural systems. The rearing and utilization of the red mason bee in orchards is a good example.