Consequently, parasite populations in published experiments may not yet have reached a local fitness optimum with respect to maize virulence traits. For example, low or no emergence was recorded on maize for S. hermonthica from two locations (Abu Naama, Sudan and Samuru, Nigeria), although both locations had high predicted habitat suitability for parasitism on maize (Fig. S2). However, in the year of each respective trial, only 2% (Sudan, 1979) or 12% (Nigeria, 1975) of total crop area harvested of maize, millet, and sorghum was planted to maize (Food and Agriculture Organization of the United Nations 2020). Thirteen years later, when relative area of maize harvested in Nigeria had more than doubled (Fig. S1), Kim et al. (1994) observed higher emergence on maize than either sorghum or pearl millet in 10 of 12 locations. Kim et al. (1994) also described poor reproductive success (post emergence) of parasites on maize relative to sorghum. If contemporary S. hermonthica populations are better adapted to maize, for example through evolution of reduced virulence but increased seed set, ENM contrasts might show stronger associations with emergence.