A revision of the subgenera Euhyboma Kolbe, 1893, Parahyboma Paulian, 1938, and Rubrohyboma Paulian, 1939 of Deltochilum Eschscholtz, 1822 (Coleoptera: Scarabaeidae: Scarabaeinae)

ABSTRACT This paper provides a revision of the three smallest subgenera of Deltochilum, all endemic to the Atlantic Forest of South America. Deltochilum (Euhyboma) and D. (Rubrohyboma) are monospecific taxa, composed of D. brasiliense (Castelnau, 1840) and D. rubripenne (Gory, 1831), respectively, whereas D. (Parahyboma) is composed of two allopatric species, D. furcatum (Castelnau, 1840) and D. granulosum Paulian, 1933. Lectotypes for D. brasiliense and D. rubripenne are designated. Each species is analyzed as follows: a detailed literature review, a diagnosis, description, illustrations of key morphological characters, list of material examined, and geographic distribution. An improved identification key to the subgenera of Deltochilum is presented.