Blue Orchard Bees are native bees and more efficient pollinators than honey bees. There are 140 species of Osmia bees. They are skilled at pollinating fruit trees-apples, pears, plums, and peaches. Most native bees are solitary. Blue orchard bees create their home out of mud. They do collect pollen and nectar for rearing their young. Blue orchard bees mix the pollen, nectar and their own saliva together before laying an egg on top of this mass. Bees further back in the nest tend to be females, while male baby bees tend to be towards the front of the nest.
https://www.fs.usda.gov/wildflowers/pollinators/pollinator-of-the-month/mason_bees.shtml