When rice is most vulnerable
Heading through milk stage. Once grains have hardened past the dough stage, further feeding causes little damage.How rice bug shows in satellite data
- No reliable satellite signature - grain damage does not show as canopy change.
- Yield-map or reports data show quality reductions (increased empty and stained grains) despite normal NDVI.
- Weather and phenology are the main triggers for scouting alerts, not imagery.
Field symptoms
- Empty, shriveled grains with dark spots at the feeding site
- Discolored, off-color panicles at milk stage
- Bugs visible on panicles in early morning and late afternoon
- Strong distinctive odor (“bug smell”) on entering the field
- Yield loss quantified only at threshing
Reduce the damage by
- Keep bunds and surrounding grasslands clean - rice bug breeds in wild grasses and moves into rice at heading.
- Synchronized planting across an area reduces the window during which flowering rice is available to the bugs.
- Early morning hand-net catching works on small plots.
- Selective insecticide (a single spray of a pyrethroid or neonicotinoid) at heading only if scouting shows more than one bug per hill.
- Do not spray after milk stage - most damage is already done.
Set an alert for early warning
Recommended settings for rice bug on rice:- Calendar reminder - schedule scouting at heading, especially on fields bordering grasslands or fallow.
- New Imagery alert during heading to prompt a scout visit even though the insect does not show in the NDVI itself.