South American Melolonthinae (Coleoptera: Scarabaeidae) classification and nomenclature: some problems and solutions

Classificatory changes are made for some taxa of New World Melolonthinae based on the examination of specimens (including type specimens) and a reevaluation of some of the characters used to justify previous classification decisions. Blepharotoma angustata (Blanchard) (new combination) is transferred from the genus Aplodema Blanchard. The Neotropical members of the genus Heteronyx Guérin-Méneville are transferred to the genus Blepharotoma resulting in the following new combinations: Blepharotoma boliviana (Moser), Blepharotoma corumbana (Moser), Blepharotoma cuyabana (Moser), Blepharotoma heynei (Moser), and Blepharotoma schencklingi (Moser). The genus Blepharotoma is transferred from the tribe Liparetrini to the tribe Sericoidini. The genus Aplodema and the junior synonym Haplodema Harold are transferred from the tribe Liparetrini to the tribe Sericoidini and synonymized with the genus Sericoides Guérin-Méneville. Sericoides magellanica (Blanchard) (new combination) is transferred from the genus Aplodema and placed as a senior synonym of Apterodema acuticollis Fairmaire (new synonymy). Ampliodactylus (new genus) is described for two southern South American species: Ampliodactylus marmoratus (Curtis) (new combination) and Ampliodactylus vestitus (Philippi) (new combination). The genus Chremastodus Solier is placed in synonymy with the genus Macrodactylus Dejean (Macrodactylini) and Chremastodus pubescens Solier is placed as a junior synonym of Macrodactylus chilensis Solier (new synonymy). Macrodactylus crassipes Philippi and Macrodactylus nigrinus Philippi are placed as junior synonyms of Macrodactylus farinosus Philippi (new synonymies). The genus Astaenosiagum Martínez is placed in synonymy with the genus Pristerophora Harold (Macrodactylini). Pristerophora longipes (Philippi) (new combination) is transferred from the genus Astaenosiagum and Schizochelus ursulus Philippi is placed as a junior synonym of this species (new synonymy). Pristerophora paulseni (new species) is described. Pristerophora picipennis (Solier) is placed as a senior synonym of Schizochelus breviventris Philippi (new synonymy) and Schizochelus serratus Philippi (new synonymy). Pusiodactylus (new genus) is described for two southern South American species: Pusiodactylus mondacai (new species) and Pusiodactylus flavipennis (Philippi) (new combination). The genus Paulosawaya Martínez and D'Andretta is placed in synonymy with the genus Clavipalpus Laporte (Macrodactylini) resulting in the new combination Clavipalpus ornatissima (Martínez and D'Andretta). The following replacement names are proposed for three junior secondary homonyms the genus Plectris LePeletier and Serville: Plectris evansi (new name) for Plectris cinerascens Moser (junior secondary homonym of Plectris cinerascens (Blanchard)), Plectris katovichi (new name) for Plectris bonariensis Frey (junior secondary homonym of Plectris bonariensis (Bruch)), and Plectris tacoma (new name) for Plectris comata (Blanchard) (junior secondary homonym of Plectris comata (Blanchard))