Taxonomic review of the subgenus Hybomidium Shipp 1897 (Coleoptera: Scarabaeidae: Scarabaeinae: Deltochilum)

The subgenus Hybomidium includes 13 species and one subspecies, of which four are new: Deltochilum (Hybomidium) bezdeki n. sp., D. (H.) carrilloi n. sp., D. (H.) molanoi n. sp., and D. (H.) louzadai n. sp. D. sublaeve Bates 1887 new status and D. panamensis Howden 1966 n. status are elevated from subspecies to species. The synonymies between D. icarus (Olivier 1789) and D. guildingii (Westwood 1835), and between D. orbignyi (Blanchard 1846) and D. chalcea (Buquet 1844) are invalidated, and the synonymy between D. guildingii and D. chalcea new synonymy is proposed; D. amazonicum Bates 1887 is proposed as subspecies of D. orbignyi (D. orbignyi amazonicum n. status). Lectotypes for D. amazonicum, D. chalcea and D. icarus are designated. Descriptions or (re)descriptions, diagnoses, remarks, figures of external morphology and male genitalia, examined material and distribution maps are presented for all species. A key to the species of the subgenus is presented in two languages (English and Spanish).