The effect of intertrap distance and chlorantraniliprole seed treatments on Mexican rice borer (Lepidoptera: Crambidae) pheromone trap capture in rice fields

The effect of intertrap distance on the number of male Mexican rice borers, Eoreuma loftini (Dyar), captured was assessed with hexagonal arrays of pheromone traps with a single trap in the center.  Arrays with intertrap distances of 5, 25, 50, 100 and 250 m were deployed in rice fields on two farms in Jefferson and Chambers Counties, TX, and the number of moths caught was recorded for 5 sampling periods.  Significant differences were detected between treatments, with the greatest numbers of E. loftini caught in traps with an intertrap distance of 250 m.  The proportion of the total moths caught by the center trap was lower than the average proportion caught in perimeter traps at 5, 25, and 50 meters.  Results indicate there is substantial interference between traps placed less than 100 m apart, and the active distance of E. loftini pheromone traps may be greater than 100 m.  A study was conducted in Calcasieu Parish, LA to assess the potential to use pheromone traps to monitor E. loftini population densities in rice chlorantraniliprole treated and untreated rice fields.  Despite having low larval infestation levels, traps surrounding insecticide treated fields caught comparable numbers of male E. loftini than traps near untreated fields.