an order of primitive wingless insects of subclass Apterygota.

The dimensions of Diplura are small (usually less than 10 mm; rarely, to 40–50 mm); the body is elongated and white or yellowish. The head is globose with long, multisegmented antennae and no eyes; the mouth parts are adapted to gnawing. There are three pairs of legs. At the posterior end of the abdomen there is a pair of cerci. In some Diplura these cerci are long and multiarticulate; in others they are chelate. Diplura are sensitive to drying; they inhabit the soil, the forest floor, anthills, or rotten wood. The majority are predators or feed on animal remains. Fertilization is external and internal. Development proceeds without metamorphosis. More than 200 species of Diplura are known; they are divided into three families—Campodeidae, Japygidae, and Projapygidae. Pro-japygidae are found in Africa and South America; Campodeidae (for example, represented by species of genus Campodea), in the central zone of the European USSR; and Japygidae, in the south (as far north as the steppe zone). Japyx ghilarovi is common in the Crimea. There are about 20 species in all in the USSR; of these the largest is Japyx dux (to 40 mm), found in Middle Asia.