Age-specific tolerance in sugarcane varieties against lesser cornstalk borer (Elasmopalpus lignosellus) feeding

Lesser cornstalk borer, Elasmopalpus lignosellus Zeller (Lepidoptera: Pyralidae), is an important sugarcane pest in southern Florida. It feeds on meristematic tissues of young sugarcane shoots and causes dead hearts, symmetrical rows of holes in the leaves, and plant death. A 2-year greenhouse experiment was conducted to evaluate sugarcane varieties for age-specific tolerance against E. lignosellus feeding damage. Three commercial sugarcane varieties (CP 78-1628, CP 88-1762, and CP 89-2143) were infested with E. lignosellus larvae at 3-, 5-, and 7-leaf growth stages. Sugarcane response to feeding was recorded as damage symptoms, tiller production, number of millable stalks, and sugarcane and sucrose yield. The sugarcane variety CP89-2143 was more sensitive to E. lignosellus damage and resulted in reduced sugarcane and sucrose yield compared with CP78-1628 and CP88-1762. These varieties were more sensitive to damage at 3-leaf stage than when infested at 5- and 7-leaf stages. Comparison of yield reduction with the E. lignosellus lethal damage (dead hearts + dead plants) showed that these varieties had equal ability to tolerate the feeding damage, but the tolerance declined with the delay in infestation time.