On the identity of Mastacanthus Suﬀrian, 1852 and Sternoglosus Suﬀrian, 1866 and key to World genera of Pachybrachina (Chrysomelidae: Cryptocephalinae: Cryptocephalini)
Pachybrachina includes 8 genera worldwide. The identity of the two Neotropical genera Mastacanthus Suﬀrian, 1852 and Sternoglosus Suﬀrian, 1866 is established. Redescription of the type species of both genera and an illustrated key to World genera are provided. The generic type species of Sternoglosus and the lectotype for S. scalaris are designated.