Adult chinch bugs,Blissus leucopterus leucopterus(Say), were inoculated with dried conidia ofBeauveria bassiana(Bals.) Vuill. and incubated in growth chambers with various host plants, liquid diet, or water. Results from these bioassays showed that mortality in the populations that had fed on sorghum and corn were reduced when compared with insects bioassayed on other food sources. More importantly, fungal presence and development in the cadavers of insects fed on sorghum and corn was significantly reduced when compared to the populations fed on other host plants, artificial diet, or water. These results indicate the presence of a plant produced fungal inhibitor fortuitously protecting the insect feeding upon it.