a subfamily of solitary wasps of the family Vespidae; it was earlier considered the separate family Masaridae.
Masarinae have been little studied. They are predominantly small forms, with a body length rarely greater than 1 cm. The abdomen is striped. The wasps feed on the nectar and pollen of flowering plants; in contrast to bees, they carry the pollen in their crop. The females build solitary nests with a single or, sometimes, several isolated cells. The nests, which are in the ground or on branches, usually are made from clay or a clay and sand mixture cemented with secretions from the salivary glands. The female deposits an egg in a cell of the nest, filling it with a mixture of pollen and nectar and then sealing it. The larva develops in the course of several months and then spins a dense cocoon inside the cell. The life cycle may last two years. There are about 100 species, distributed mainly in desert zones.
In the USSR, the wasps occur in the southern European portion, in Transcaucasia, and Middle Asia.