Economic threshold and economic injury level of Mythimna separata (Walker) on rice.
The most injurious fifth-instar larvae of Mythimna separata (Walker) were released in five fixed densities of 1 to 10 larvae/bill under the cages at the most vulnerable panicle stage of Kranti’ variety of rice in the field (zero larva as the control) in the rainy season of 1980–81. The leaf area consumed, number of spikelets and grains fallen, weight of total grains fallen, and yield loss were more due to higher larval densities of 7 and 10 than in the lower ones of 1 and 3/hill. The avoidable yield loss ranged from 12.82 to 35.89 percent, i. e. 125 to 35.0 q/ha, by 1 to 10 larvae/hill.