Original description: Frolov et al., 2019
Locality: Ecuador, Zamora-Chinchipe, Alto Marzo.
Diagnosis. This species differs from O. inexpectatus in the sculpture of the body: head is punctate with transversely elongate, sometimes adjoining punctures (punctures are round and relatively sparse in O. inexpectatus); pronotum with coarser ocellate punctures (punctures are smaller and not ocellate in O. inexpectatus); elytra with characteristic U- to V-shaped punctures each bearing a distinct yellowish seta posteriorly (punctures are round in O. inexpectatus; setae in the punctures are smaller, barely visible at the same magnification).
Distribution. The new species is known from only one locality, Alto Marzo in Zamora-Chinchipe province of Ecuador.
Frolov A. V., Akhmetova L. A., Vaz-de-Mello F. Z. 2019. Contribution to the knowledge of the Neotropical canopy dwelling genus Onorius (Coleoptera, Scarabaeidae, Orphninae): another species from southern Ecuador and notes on the hind gut morphology in the Orphninae. Journal of Natural History. 53 (17–18): 1071–1077.