All the known taxa, up to Spring 2013, of this genus from Japan (39 species and 193 subspecies) are described and illustrated with superb, high quality, full colour photographs. The first, general section, includes terminology, key to the species, regions and prefectures of Japan and islands of Japan; the second section contains the species descriptions. For each species the photographs show the adult, together with magnified structural detail, including genitalia; specimens illustrating geographical variation and all the known subspecies, with genitalia. Species description includes: original description, history of research, type locality, type depository, morphology, molecular phylogeny, distribution, habitat, bionomical notes, geographical variation, conservation and etymology. Detailed distribution maps indicating the type locality are given for all the species and subspecies. Some ecological photos taken in the field are also given for more than half of the species.