Penthicodes celebica n. sp., is described from Sulawesi, P. warleti n. sp. from India (Assam) and P. caja malayana n. ssp. from peninsular Malaysia. They are compared with the allied species of the subgenus Ereosoma Kirkaldy, 1906, as treated by Nagai & Porion (1996): P. astraea (Stål, 1864), P. atomaria (Weber, 1801) P. bimaculata (Schmidt, 1905), P. caja (Walker, 1851), P. pulchella (Guérin-Méneville, 1838), P. quadrimaculata Lallemand, 1963, P. rugulosa (Stål, 1870) and P. variegata (Guérin-Méneville, 1829). Penthicodes quadrimaculata is removed from synonymy with P. bimaculata. Male genitalia of all treated species are illustrated and described. New geographical records, distribution maps, behaviour data and photographs of habitus are given. An illustrated identification key to all 12 species of the genus, including P. farinosa and P. nicobarica, is proposed. Penthicodes basigera (Walker, 1870) is transferred to the genus Scamandra Stål, 1863 and the new combination Scamandra basigera (Walker, 1870) n. comb. is proposed. The subgenus Ereosoma is regarded as heterogenous and the species are separated in 2 new species-groups on the base of the male genitalia and colour pattern: group astraea+ (astraea, bimaculata, caja, celebica, quadrimaculata, rugulosa and variegata) and group atomaria+ (atomaria, pulchella, warleti).