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Rice gall midge (Orseolia oryzae in Asia, O. oryzivora in Africa) larvae feed inside the growing point of tillers. The plant produces a tubular, hollow, silver-white “silver shoot” (also called onion leaf or ginger shoot) instead of a normal leaf. Affected tillers never produce a panicle. High-yielding varieties without a Gm resistance gene can lose more than 60% of tillers in outbreak conditions.

When rice is most vulnerable

Tillering. Once panicle initiation has passed, new gall-midge attack cannot damage yield (the panicle is already committed).

How gall midge shows in satellite data

  • Reduced tillering across affected zones shows as lower-than-expected NDVI during tillering.
  • Signature overlaps with N deficiency, poor soil, and zinc deficiency; separate with ground scouting for silver shoots.
  • Once heading passes and non-panicle tillers are visible, the yield loss is already locked in.
Gall midge looks like nutrient deficiency from above. If a top-dressing does not green up the affected zones and silver shoots are visible on scouting, suspect gall midge.

Field symptoms

  • Silver-white, tubular, hollow “silver shoot” replacing a normal leaf on affected tillers
  • Affected tillers do not produce a panicle
  • Reduced total tillering, uneven canopy height
  • Damage is heaviest in shaded, humid, weedy plots and in staggered-planting areas

Reduce the damage by

  • Grow resistant varieties carrying Gm genes - by far the most effective control.
  • Synchronized planting across a whole area breaks the continuous breeding cycle.
  • Destroy volunteer rice and grassy weeds on bunds and fallow between seasons.
  • Reduce shading and improve drainage where possible.
  • Selective insecticide (chlorantraniliprole) only if scouting justifies it during tillering. Carbofuran, long used for this, has been banned in Malaysia since 2023 - see Pesticide registration.
  • Do not rely on late-season insecticide - once silver shoots appear, damage is already done.

Set an alert for early warning

Turn the diagnosis into a trigger. Focus alerts on the tillering window so silver shoots are caught while additional damage can still be prevented.
Recommended settings for gall midge on rice:
  • NDVI threshold alert during tillering on susceptible varieties.
  • New Imagery alert in the tillering window on fields with a history of gall midge.