Nomenclatural clarification on some Southern African monkey beetle genera (Scarabaeidae: Hopliini: Pachycnemina)

After an extensive revision of the literature, we come to the following conclusions concerning the nomenclature of Southern African monkey beetles of the subtribe Pachycnemina: firstly, the current usage of the nominal subgenus Pachycnemula Schein, 1959 for a subgenus taxon different from Pachycnema s. str. Le Peletier de Saint-Fargeau & Audinet-Serville, 1828 is incorrect since both names share the same type species— Melolontha crassipes Fabricius, 1775—and are therefore objective synonyms. Hence, here we invalidate Pachycnemula and establish the new nominal subgenus Macacoplia Cupello & Ribeiro-Costa to denote the subgenus taxon currently known as Pachycnema ( Pachycnemula ). Secondly, we discuss the different spellings of the nominal genus Lepithrix Le Peletier de Saint-Fargeau & Audinet-Serville, 1828, which was originally established as Lepitrix but emended to Lepithrix in 1913 by Dalla Torre. Although originally an unjustified emendation, the Lepithrix spelling is currently in prevailing usage and therefore should be deemed a justified emendation according to Article 33.2.3.1 of the current edition of the International Code of Zoological Nomenclature. That being so, it becomes necessary to acknowledge the homonymy between Lepithrix Le Peletier de Saint-Fargeau & Audinet-Serville and its junior homonym Lepithrix Neitner, 1857, current junior synonym of Loxoncus Schmidt-Gobel, 1846 (Carabidae: Harpalinae: Harpalini: Stenolophina).