Material examined. COSTA RICA: 3♀♀ ex Leopardus pardalis (USNMENT985399): these ticks correspond to the original material used by Neumann (1899) to describe I. affinis, and it is labeled as “ Ixodes ricinus Linnaeus, Felis pardalis, U.S. Nat. Mus. Coll. Marx, No. 41-2”; 3♀♀ 2♂♂ ex Odocoileus virginianus (USNMENT985448); 2♂♂ ex horse, Guanacaste (USNMENT985400); 1♂, Guanacaste (USNMENT985389). All the females correspond to semi-engorged specimens.