The new sp. is described, illustrated and compared with O. arizonicus Kenn. Holotype <J: Michoacan state, Los Azufres, Arroyo San Pedro, 4 km NW of San Pedro J£cuaro, alt. 2295 m, 29-XI-1998; allotype $, same data, but 18-XI-1989; deposited at CNIN, UNAM, Mexico. Its discovery in central Mexico represents a notable southern extension of the range of this genus in America.