Mexican Rice Borer Eoreuma loftini (Dyar) (Fig 2B). As they bore into the stem or The Mexican rice borer is a spherical, globular, cream-colored stalk, Mexican rice borer larvae pack devastating pest of sugarcane eggs hidden between the folds of tunnels with frass, which prevents the and a serious pest of rice. It was dried leaves. After hatching, young entry of predators or parasites (Fig. first collected in Louisiana in two larvae feed inside fresh leaf sheaths 3). Pupation takes place inside the pheromone traps on Dec. 15, 2008, and then bore into the stem or stalk. stem or stalk after mature larvae have near two rice fields northwest of This feeding causes an orange made moth emergence holes that Vinton, La. discoloration of the leaf sheath. are smaller than those made by the 1. Identification — Mexican rice Mexican rice borer larvae are whitish sugarcane borers in sugarcane. borer adults are light tan moths with with a light-colored head capsule 2. Injury to rice & sugarcane — delta-shaped wings (Fig. 1A). By and two pair of dark purple stripes Rice injury begins with feeding in comparison, sugarcane borer adults running the length of the body (Fig. leaf sheaths. Borers then tunnel are larger, straw-colored moths about 2A). By comparison, sugarcane borer inside the stem. Signs of early injury 3/4-inch long with a series of black larvae are yellowish or white with a in rice are withering and death of the dots arranged in an inverted V-shape series of brown spots on the back youngest leaf, resulting in a condition pattern on the front wings (Fig. 1B). called deadheart (Fig. 4A). Most Mexican rice borer adults produce infestations are not obvious until after the boot stage. Stem feeding during panicle development causes partial or complete sterility and the white- head condition (Fig. 4B). The white, empty panicles are lightweight and stand upright. Feeding inside the stem can also cause plants to lodge before harvest. Fig. 2A) Mexican rice borer larva; Fig. 2B) Fig. 1A) Mexican rice borer adult; Fig. 1B) Sugarcane borer larva. (A. Meszaros and Sugarcane borer adult. (F. Reay-Jones and J. Saichuk) T. Riley) Sugarcane injury results in a In sugarcane, scouting should begin decrease in sugar production, and when visible internodes are seen under heavy pressure can cause in most plants and continue on a stunting and/or lodging of the stalks. regular basis. Pheromone traps can Infestations in sugarcane can be so assist in monitoring for Mexican rice severe that harvesting fields becomes borer adults in rice and sugarcane. If unfeasible. pheromone traps are used, scouting should begin when 20 moths are 3. Scouting rice & sugarcane — In collected in a trap during a one-week rice, scouting should begin at green period. ring and intensify when plants reach the early boot stage. Look at the leaf 4. Management — Consult sheath for orange lesions caused by your county agent for the latest larval feeding. Avoid confusing these recommendations to control the lesions with sheath blight injury. To Mexican rice borer. Fig. 4A) Dead heart; Fig. 4B) White-head confirm Mexican rice borer injury, condition. (J. Saichuk) peel off the leaf sheath to expose the Report the Mexican Rice Borer feeding larva or to detect frass (Fig. 5). If you suspect you have found a Mexican rice borer infestation, report it to your local county agent or contact the Louisiana Department of Figure 5) Feeding lesion - an orange Agriculture and Forestry at (225) 952- discoloration of the leaf sheath. (J. Saichuk) 8100. Authors: Natalie Hummel, Gene Reagan, Dale Pollet, Visit our Web sites Waseem Akbar, Julien Beuzelin, Chris Carlton, Figure 3) Mexican rice borer larvae pack www.lsuagcenter.com or Johnny Saichuk, Tad Hardy (LDAF) and Mo sugarcane tunnels with frass. (F. Reay-Jones) www.ldaf.state.la.us Way (Texas AgriLife) Louisiana State University Agricultural Center, William B. Richardson, Chancellor • Louisiana Agricultural Experiment Station, David J. Boethel, Vice Chancellor and Director • Louisiana Cooperative Extension Service, Paul D. Coreil, Vice Chancellor and Director • The LSU AgCenter provides equal opportunities in programs and employment. Louisiana Department of Agriculture & Forestry Mike Strain DVM, Commissioner • LSU AgCenter Pub. 3098 12/08.