Symmorphus is a primarily holarctic genus of potter wasps. Species within this genus are present in most of Europe, in East Palearctic ecozone, in the Near East and in the Oriental ecozone. These mall solitary wasp can reach a length of about 1 centimetre (0.39 in). They nest in pre-existing cavities (twigs, stems, galls, old nests of other Hymenoptera, hollows in the wood). Partitions between cells are made of mud. Adult females prey on caterpillars and larvae of beetles to lay eggs in them.