Proctolaelaps bickleyi (Bram) (Acari: Melicharidae) is an edaphic predatory mite commonly associates with insects. Although P. bickleyi has been reported from many countries worldwide, it is reported herein for the first time in Japan from laboratory cultures of Chilo suppressalis (Walker) and Cossus insularis (Staudinger) (Lepidoptera: Crambidae, Cossidae). Proctolaelaps bickleyi is redescribed and illustrated from females, males, deutonymphs, protonymphs and larvae. The morphological ontogeny of idiosomal and leg chaetotaxy is discussed and a key to the Japanese species of Proctolaelaps is provided.