The genera Epilissus Reiche, 1841, and Arachnodes Westwood, 1847, are redefined. Both genera can be separated by the shape of external border of mesepimeron and by the structure of the inner margin of dorsal side of protibiae. A large number of species previously placed in Arachnodes are transferred to Epilissus, and four species are transferred to a new genus, Apterepilissus n. gen. which presents intermediary characters between Epilissus and Arachnodes, and which is additionaly characterized by the lack of wings, a globulous body shape and widely spaced clypeal teeth. Monophyly of the “Epilissus group”, composed of the genera Epilissus, Arachnodes and Apterepilissus n. gen., is supported by the presence of a small carina-shaped relief near the posterior lateral edge of the metasternum. Peyrierasantus Paulian, 1976, and Pseudarachnodes Lebis, 1953, are synonymized with Arachnodes. Two new species of Epilissus, E. fantamattii n. sp. and E. andranobeensis n. sp., and three new species of Arachnodes, A. bicolor n. sp., A. viettei n. sp. and A. zombitsyensis n. sp., are described and compared with their most related species. New synonymies are proposed: Arachnodes johanni Lebis, 1953, new synonym of Arachnodes delaunayi Lebis, 1953; Epilissus colasi Paulian, 1935, new synonym of Epilissus hova Künckel d’Herculais, 1887, n. stat.; Arachnodes sicardi Lebis, 1953, new synonym of Epilissus alluaudi (Lebis, 1953); Arachnodes vadoni Lebis, 1960, new synonym of Epilissus emmae (Lebis, 1953); Epilissus prasinus antongilensis Lebis, 1953, new synonym of Epilissus prasinus (Klug, 1833); Arachnodes splendidus descarpentriesi Montreuil, 2006, new synonym of Arachnodes splendidus descarpentriesi Lebis, 1953. As a result of homonymy within the genus Arachnodes between Arachnodes nitidus (Castelnau, 1840), originally described as Circellium, and Arachnodes nitidus (Paulian, 1976), originally described as Peyrierasantus, the name Arachnodes neonitidus n. nom. is proposed to replace the name introduced by Paulian. These results are all listed in the catalogue of the genera Arachnodes, Epilissus and Apterepilissus n. gen.
Insecta, Coleoptera, Scarabaeidae, Epilissini, Arachnodes, Pseudarachnodes, Peyrierasantus, Epilissus, Apterepilissus n. gen., Madagascar, new genus, new species.