a mite of the group Acari-formes. The mite parasitizes the larvae of insects that are pests of grain crops (Angoumois grain moth, jointworms). The sexually immature female is oblong, reaching 0.2 mm in length. The female gives birth to 200 to 300 mites, which undergo their entire development in the maternal body. Because of this, the posterior part of the female’s body becomes spherical. The males, which are born first, fertilize the females after they emerge. During periods of mass reproduction, P. ventricosus attack workers in grain storehouses, causing a severe skin irritation called grain itch.