Location and parasitism of Diatraea saccharalis (F.) by Cotesia flavipes (Cameron) were compared between hosts fed either conventional or transgenic sugarcane expressing Galanthus nivalis L. agglutinin (GNA) under choice and no-choice conditions. In olfactometer experiments, females of C. flavipes randomly visited the different odor zones available but spent significantly more time in odor zones corresponding to plants damaged by D. saccharalis versus blank (control) odor zones. However, they spent similar amounts of time in odor zones corresponding to damaged transgenic and conventional sugarcane. Laboratory and field-cage experiments showed that C. flavipes equally parasitized D. saccharalis feeding on transgenic and conventional sugarcane plants. Moreover, sex ratio and brood size of C. flavipes were similar on hosts fed transgenic or conventional sugarcane. The results of this study suggest that transgenic sugarcane expressing GNA would not significantly affect host location and parasitism of D. saccharalis by C. flavipes in the field.