During an expedition to Peru in August 2010, a new species of otopheidomenid mite, Prasadiseius incanus Prasad and Guanilo, n. sp. (Acari: Otopheidomenidae), was collected from Xylophanes fusimaculata (Felder, 1874) and Xylophanes undata Rothschild and Jordan, 1903 (Sphinghidae). The female and male of the new species are described using current nomenclature for the idiosomal chaetotaxy and illustrated in a series of photographs. A key for the identification of all species of the genus is provided.