Currently, no single source of greenbng [Schizaphis graminum (Rondani)] resistance in wheat (Triticum aestivum L.) germplasm available to wheat breeders provides resistance to all known greenbug biotypes in the field. Therefore, two sources of resistance are being combined in several wheat breeding programs. This requires the evaluation of progeny for reaction to two greenbug biotypes instead of one. Our objective was to test the efficacy of infesting seedlings in the greenhouse with green bugs of two biotypes simultaneously. Such a procedure, if feasible, could economize breeding protocols. OK81322, resistant to biotypes B and C, a ‘Largo’ derivative, resistant to biotypes C and E, and F1, and F2, progeny from the crosses of these genotypes were infested with a 1:1 mixture of biotypes B and E greenbugs. All plants of both parental genotypes were susceptible, all F1, plants were resistant, and the population of F2, plants segregated for greenbug resistance. Results indicated that evaluation of breeding material with mixed greenbug populations is reliable, and this technique should be more efficient than conducting separate biotype tests.