Pemphredon species are closely related to the Ammophila species. However they are much smaller, some measuring no more than 0.2 centimeters. Their body is also much shorter, for they lack the prolonged waist common in the Sand Digger Wasps. Their larvae feed on cicadas, plant lice or even thrips, which mother hides in existing openings in wood, twigs or reet, rather than digging one in the ground. There are some 800 species world wide.