Yellow Stem Borer Control

Symptoms

Yellow stem borer (Scirpophaga incertulas) is the most damaging borer of rice. The pale yellow caterpillar bores into the stem. In the vegetative stage the central shoot dries and can be pulled out easily, called dead heart. At the panicle stage the whole earhead turns white and empty, called white ear or white head. Small holes and frass may be seen on the stem. The moth is yellowish with a black spot on the female forewing.

Damage

Dead heart at the vegetative stage and white ears at the panicle stage directly reduce the number of productive tillers and filled grains. Yield loss commonly ranges from 10 to 30 percent and can be higher in heavy infestation. Late planting and high nitrogen worsen the damage.

Organic & cultural control

Clip and destroy egg masses on leaf tips before transplanting. Cut leaf tips at transplanting to remove eggs. Pull out and destroy dead hearts. Release the egg parasitoid Trichogramma japonicum on cards at recommended intervals. Use light traps and pheromone traps to monitor and trap moths. Avoid excess nitrogen and remove stubble after harvest to kill overwintering larvae.

Chemical control

Granular insecticides such as cartap hydrochloride 4G or chlorantraniliprole 0.4G applied into standing water at tillering give good control, and sprays of chlorantraniliprole 18.5 SC, flubendiamide or cartap hydrochloride are used when borer activity is high. Apply at egg hatching or early dead heart stage for best effect. Always follow the product label dose, observe the pre-harvest interval, and consult your local KVK or agronomist before applying.

Always follow the product label, the recommended pre-harvest interval, and your local KVK or agronomist. Pesticide approvals change, so verify before use.

Prevention

Transplant on time, avoid late planting, use recommended balanced nitrogen, choose tolerant varieties, clip seedling tips, and destroy stubble and volunteer plants after harvest. Monitor with pheromone and light traps and keep field bunds clean.