Rice Bug
Leptocorisa oratorius F. and Leptocorisa acuta Thunberg. are the common species of rice bug. It sucks the contents of rice grains from pre-flowering spikelets to soft dough stage that causes empty or unfilled grains and discoloration.
What are the symptoms?
Check for the presence of insect:
√ Eggs - oval, shiny, and reddish brown eggs along the midrib of leaf
√ Nymphs - slender and brown-green nymphs and adults feeding on endosperm of rice grains
√ offensive smell
Check for damage:
√ small or shriveled grains,
√ deformed or spotty grains,
√ empty grains, and
√ erect panicles.
Impact to the crop
Both adults and nymphs feed on grains at milking stage. They can be serious pests of rice and sometimes reduce yield by as much as 30%.
How to control?
√ Removal of weeds from fields and surrounding areas
√ Level fields with even applications of fertilizer and water
√ Synchronized crop planting.
√ Use of biological control agents like wasps, grasshoppers and spiders attack rice bugs or its eggs.
√ Chemical Control - use of insecticide registered for control of rice bugs
Source: http://www.knowledgebank.irri.org