The morphological ontogeny of Achipteria nitens (Nicolet, 1855) from Crimea peninsula is redescribed and illustrated, and ecology and some biological parameters of this species are investigated. The larva of this species has short, thick and barbed setae in and of c-series, and anterior part of prodorsum reticulate, whereas the nymphs have most gastronotal setae of medium size and barbed, except for shorter c3, and shorter, thick and smooth p2 and p3. A key to the larva and nymphs of eight species of Achipteria Berlese, 1885 is provided.
Keywords: Acari, oribatid mites, juveniles, leg setation, ecology, stage structure.