Leaf-cutting bees are solitary bees that create small tubes, made from circular sections of leaves, for their larvae to live in. Evidence of the bees will be leaves on plants with numerous circular sections cut from their margins, as well as the small tubes tucked into many holes or crevices. They are excellent pollinators, their activity on plants does not harm the plant, and they are unlikely to sting without serious provocation. Holes in wood siding or stucco that contain the leaf tubes were not created by the bee, but already were present and discovered by the bee in its search for suitable places for its larvae. Occasionally they will scoop out rotted or softened wood to create the chamber, or simply place the leaf tube on window ledges, under siding or roof materials, along fence junctions, or any other convenient crevice. The larvae feed on a paste of pollen and honey provided by the female.
There is no need to control these beneficial and relatively harmless bees. If the placement of the leaf tubes is undesirable then the available holes and crevices can be filled or sealed.