Identification

The adult moth is whitish brown, with two long black stripes on each wing and one short black stripe in between (Fig.1). Wing span is about 13 to 18 mm. Early larval instars are green and late instars olivine/orange with brown or black heads (Fig.2). Larvae are from 8 to 25 mm long. The egg is jelly-like, flat and transparent (Fig 3).

Damage symptoms

Longitudinal white and transparent streaks on leaf blades are created (Fig.2). Older larvae spin silk and vertically roll leaves and feed on leaf mesophyll tissues inside.

Economic importance and control options

Feeding damage of RLR during the vegetative stage may not cause significant yield losses. The damage may be more important at the late tillering or reproductive stage when it affects more than half of the flag leaf and the next two youngest leaves in each tiller.

Cultural control: overuse of fertilizer (particularly Nitrogen) should be avoided as tender green leaves attract ovipositon of RLR. Where possible grow resistant varieties.

Biocontrol: During adult population peaks (especially for the second generation), release Trichogramma at a rate of 40,000 wasps per acre (100,000 per ha), three times. The first application may not be done before 20 days after transplanting, re-apply at 2 weeks intervals.

Chemical control: if needed and Trichogramma cards are not available, a pesticide may be used according to the label instruction (see green and yellow list for details).