Integration of control tactics for management of the sugarcane borer (Lepidoptera: Pyralidae) in Louisiana sugarcane

A 3-yr split-split-plot study was conducted to evaluate the contributions of arthropod predation, varietal resistance, and insecticidal control toward the management of the sugarcane borer, Diatraea saccharalis (F.) in sugarcane (a complex hybrid of Saccharum spp.). The study helped to quantify the value of multiple control tactics in pest management. Insecticidal control was the predominant factor preventing plant injury by the sugarcane borer, supplying 60% of the overall control. However, varietal resistance was almost as effective as insecticidal control at suppressing moth emergence, each contributing 42% and 47% control, respectively. Even a moderately resistant sugarcane variety, CP 65-357, substantially reduced moth emergence. However, the relative contribution of varietal resistance of CP 65-357 toward control was diminished in a year with high sugarcane borer population pressure. A significant interaction (P 0.05) was detected between varietal resistance and insecticidal control, indicating greater insecticidal suppression of adult emergence on the susceptible and moderately resistant varieties than on the resistant variety. Despite this limited incompatibility, greater sugarcane borer control was always obtained with the incorporation of additional management factors. The resistant variety, CP 70-330, was shown to have a reduced potential for yield loss with the removal of insecticidal control. This study showed that the importance of a particular management tactic was increased when the relative contributions of other control tactics were reduced. Additionally, greater increases in sugar yields were detected when insecticidal control was used in combination with arthropod predation than without predation