Mexican Rice Borer Control Tactics in United States Sugarcane

The invasive Mexican rice borer, Eoreuma loftini (Dyar), expanded its range from Mexico to South Texas in the early 1980s. By 2008 the pest had moved into sugarcane- and rice-growing areas of East Texas and Louisiana, and by 2012 it was reported on noncrop host plants in Florida. Efforts to suppress E. loftini in United States sugarcane with chemicals and biological control agents were unsuccessful, so both tactics were discontinued, and E. loftini infestation of sugarcane has continued unchecked. During the last 15 years, however, research has focused on the pest’s ecology, improved insecticides and scouting methods, the identification of sugarcane resistance mechanisms, and new cultural tactics. A surveillance technique was developed that indicates when larvae are most vulnerable to insecticide sprays. Currently, registered insecticides for E. loftini control are not widely applied, although some show promise, including an insect growth regulator. A number of potentially useful cultural practices are available, including plowing under fallow stubble, judicious use of fertilizer, adequate irrigation, avoiding proximity to E. loftini-susceptible maize cultivars, and enhancement of natural enemy populations. Demonstrated and potentially useful sugarcane resistance mechanisms involve physiochemical attributes, physical characteristics, and transgenic cultivars.