Figure 1. Southern Texas and 4 states in northeastern Mexico. The filled circle in southern Texas indicates the locality in which Catarina virus is enzootic. The star in San Luis Potosí indicates the location of the study site (23°49′5′′N, 100°49′54′′W). Antibody (immunoglobulin G) to Whitewater Arroyo virus previously was found in white-toothed woodrats (Neotoma leucodon), a Mexican woodrat (N. mexicana), and deer mice (Peromyscus spp.) captured in Nuevo León; white-throated woodrats (N. albigula) and white-toothed woodrats captured in San Luis Potosí; and deer mice (Peromyscus spp.) and a southern plains woodrat (N. micropus) captured in Tamaulipas (M.L. Milazzo, unpub. data).