We describe variation in body size and color in adults of the corn leafhopper Dalbulus maidis (DeLong & Wolcott) in Mexico from 21 sites at Nearctic and Neotropic latitudes, from low (< 700 m) and high (> 700 m) elevations, and wet season (June) and irrigated dry season (October) maize habitats. Female and male leafhoppers from more northern Nearctic latitudes were larger and darker than leafhoppers from southern Neotropical latitudes. Elevation did not affect size or color of male or female corn leafhoppers. At irrigated sites where maize is grown all year, females and males collected in June had longer wings than leafhoppers collected in October. At non-irrigated sites where maize is grown only during the wet season, female leafhoppers collected in October had longer wings, a larger head, and were darker in color than females collected in June. When compared to leafhoppers living in irrigated maize habitats, D. maidis from maize habitats cultivated only in the wet season have significant variation in body size and color, suggesting D. maidis adapts morphologically to survive periodic harsh environments.