Population dynamics of the Mexican rice borer, Eoreuma loftini (Dyar), in commercial Louisiana sugarcane

Lepidopteran stem borers, the sugarcane borer (Diatraea saccharalis) and the Mexican rice borer (Eoreuma loftini), are the most damaging insect pests in Louisiana sugarcane. Currently, the integration of chemical control and areawide adoption of resistant cultivars is the best management practice to control borers. However, the impact of resistant cultivars on the seasonality of the Mexican rice borer is poorly understood in SW Louisiana due to its status as a recent invasive pest. Var. ‘L01-299’ (resistant) is the most widely grown variety in the state, and ‘HoCP14-885’ (susceptible) is a newly released variety. For this experiment, six paired fields in Vermilion Parish were selected based on history with borer pressure. Pheromone traps were placed on opposite corners of each field and monitored for adult moths biweekly. Fifty stalks within 20 m of each trap were destructively sampled and examined for larvae biweekly from May until harvest. Larval stage and bored internodes were recorded. The data was subjected to GLMM in SAS using PROC GLIMMIX, and means were separated using Tukey’s HSD (α = 0.05). Variety, time, and location were treated as fixed effects, and trap number was treated as a random effect. H₀ = both species of adult and larval populations are equally represented in each location and variety.