Designation and Reaction of Three Biotypes of the Greenbug Cultured on Resistant and Susceptible Species of Sorghum12

Eight of 1761 varieties and hybrids among different species of sorghum were found to have a high degree of resistance to 3 biotypes of Schizaphis graminum (Rondani). When preference, fecundity, and longevity were studied. biotypes on the resistant and susceptible sorghum showed marked differences in development. Development of resistant sorghums by transfer of resistant germ plasm through breeding to adapted varieties would eliminate the need for insecticidal control of greenbugs attacking sorghum.