- The caterpillar damages rice by feeding on leaves.
- The pest appears in the field sporadically in large swarms and eat away the crops in the entire field and move to other fields.Hence it is called as Swarming caterpillars or Army worms.
- If the nursery and early stages of the crop are attacked the plants are reduced to mere stumps.The pest is severe generally during puncha season.
Walk diagonally in a 0.4 Ha area and make 25 sweeps and collect the caterpillars and count. Sweeping need be conducted only during vegetative phase of the crop.