Restricted. Asia, Oceania. In American Samoa, Australia, Fiji, French Polynesia, Guam, New Caledonia, Northern Mariana Islands, Papua New Guinea. Samoa, Solomon Islands.
In Asia, minor rice pest; in Fiji, major pest on high-yielding varieties beginning in 1970s. Also on maize, wild grasses.
Larvae eat inside tunnels of folded or bound leaves, creating long white stripes. Fields appear grey.
Eggs laid singly or in small groups, overlapping in rows, often on tallest plants. Larvae yellowish-green with pale-brown heads, up to 11 mm, feed together initially then disperse. Pupate on leaves. Adults pale-yellow wings with grey-brown borders, wingspan 13 mm, with 3-4 bands.
Natural enemies: many egg and larval parasitoids and predators. In Fiji, Trichogramma and Trathala flavo-orbitalis destroy >40% of larvae.
Biosecurity: introduction possible on produce contaminated with infested stems of host plants.
Cultural control: increase plant spacing; fallow land or rotate crops; do not over-fertilise; remove weeds within and around crops; do not ratoon crops; flood fields after harvest or plough in straw and stubble; resistant varieties (new, high-yielding varieties susceptible).
Chemical control: use neem, abamectin, or spinosad. Avoid broad-spectrum products.