The Mexican rice borer, Eoreuma loftini (Dyar), is an invasive species which originated from Mexico and is threatening to cause major economic losses to the sugarcane, Saccharum spp., and rice, Oryza sativa L., industries in Louisiana. Based on the average rate of spread through the Texas rice belt and the current location of E. loftini in Texas, the insect is expected to reach sugarcane and rice production areas in Louisiana by 2008. When all sugarcane in Louisiana becomes infested, an annual loss in revenue of $319 million would be expected for cultivars similar in susceptibility to LCP 85-384 (with no irrigation and no effective insecticidal control). Applications of 30 cm of water are projected to reduce damage costs by $149 million. In the absence of insecticide applications on rice, a loss in revenue of $45 million is expected. A 31% reduction in loss in revenue is expected with one application of lambda-cyhalothrin, and an 11% reduction with two applications on rice. The rapid deployment of more permanent management tactics will provide a key role in reducing the anticipated economic impact of E. loftini once it becomes an established pest in Louisiana sugarcane and rice.