Little is known about insect and plant diversity in the regions of origin of many cultivated plants. Maize (Zea mays subsp. mays) was originally domesticated in Mexico from the wild annual teosinte Zea mays subsp. parviglumis.The first objective of this study was to compare the diversity of herbivore leafhoppers (Hemiptera: Cicadellidae) in annual teosinte and maize habitats. The second was to characterize plant species diversity in the annual teosinte habitat and its possible influence on the diversity of leafhoppers. Leafhopper adults were collected within the region of origin of maize from teosinte and maize plants during the wet season of 2016 and 2017, whereas teosinte and teosinte-associated plants were collected during the wet season of 2017 only. A higher level of leafhopper diversity was observed in the teosinte habitats (H′ = 2.33 ± 0.12) than in the maize fields (H′= 0.62 ± 0.16), with a 50% reduction in leafhopper species diversity seen in the maize sites compared with the teosinte sites. Within the maize fields, Dalbulus maidis (DeLong) (Hemiptera: Cicadellidae), which is the most important leafhopper pest in maize throughout the Americas, was the most abundant leafhopper species. Plant diversity in the teosinte sites was high, ranging between H′ = 2.16 ± 0.34 and H′= 2.45 ± 0.14. In total, we registered 174 species of vascular plants, belonging to herbs, shrubs, and trees into the teosinte sites. In addition, a significant correlation was found between some leafhopper subfamilies and plant families in these teosinte sites.