Resistance Mechanisms of Sugarcane to Mexican Rice Borer (Lepidoptera: Pyralidae)

Abstract

Larval antibiosis and adult and larval nonpreference studies were compared with field screening studies to determine the sugarcane characters and mechanisms that may confer resistance against the Mexican rice borer, Eoreuma loftini (Dyar). Larval antibiosis results of diet incorporation bioassays suggest the presence of antinutritional components or allelochemicals in some genotypes. Differences in adult oviposition among genotypes in laboratory, greenhouse, and field studies were slight; therefore, ovipositional preference is probably not important in conferring resistance. Laboratory experiments indicated that differences in larval establishment could be an important resistance character. Field results confirmed earlier research that sugarcane genotypes vary in their level of injury to this pest. However, field results did not always compare favorably with laboratory results, suggesting that several mechanisms of resistance may be important in this sugarcane-stalkborer system.