Symptoms
Circular patches of brown burnt rice (hopper burn). Plants collapse from the base. Heavy populations visible at base of tillers. Transmits grassy stunt and ragged stunt viruses. Can cause total crop loss in severe outbreaks.
Prevention
Plant resistant varieties. Avoid excessive nitrogen. Drain fields periodically to reduce humidity at base. Use balanced fertilization. Preserve natural enemies by avoiding broad-spectrum insecticides.
Treatment
Organic
Preserve natural enemies: spiders, mirid bugs, Cyrtorhinus lividipennis. Drain fields to reduce habitat. Apply Beauveria bassiana. Avoid pesticide resistance by using selective insecticides only.
Chemical (last resort)
Apply buprofezin or etofenprox for resistant populations. Rotate insecticide classes strictly to prevent resistance build-up. Never use broad-spectrum pyrethroids — causes BPH population explosions by eliminating natural enemies.
Affects 1 crop
Sources
MARDI Rice Pest Guide; IRRI Brown Planthopper Management