The morphological ontogeny of Pilogalumna tenuiclava (Berlese, 1908) is redescribed and illustrated. The prodorsal setae of juveniles are of medium size or long and barbed, and bothridial seta is fusiform, with thick, barbed head. Larva has 11 pairs of gastronotal setae, including h2, most are short and smooth, except for longer and barbed c2, c3, dp, h1 and h2. The nymphs have 15 pairs of these setae, most are short and smooth, except for longer and barbed c3. Gastronotal shield of juveniles is poorly developed, with setae of d-, l-series, and h1 in the larva, and d-, l-, h-series and p1 in the nymphs, setae of c-series, p2 and p3 are inserted on unsclerotized integument. In all juveniles, a humeral organ is present.