Identification and Quantification of Major Insect Pests of Rice and Their Natural Enemies

This survey was conducted in rice field during kharif season of year 2017 at Pusa farm of Dr. Rajendra Prasad Central Agricultural University, Samastipur, Bihar. The rice stem borer, leaf folder and plant hopper are the major insect pest of rice in Pusa region. Rice ecosystem favorable for proliferation of insect-pests is equally congenial for multiplication of the natural enemies of these pests. The month of August and September is identified as the peak activity period for most of the insect pests in sweeping net and hand picking method. Yellow stem borer (Scirpophaga incertulas), leaf folder (Cnaphalocrocis medinalis) and brown plant hopper (Nilaparvata lugens) were found as the dominant species at Pusa. In species composition study, Scirpophaga incertulas (YSB) is the dominant species of rice stem borer, Cnaphalocrocis medinalis was the dominant species of leaf folder and Nilaparvata lugens is the dominant species of plant hopper. The important predators observed in the rice ecosystem of Pusa are spider, lady bird beetle, staphylinid beetle, green mirid bug, dragonfly and damselfly. Predatory spider, dragonfly and damselfly were found most active during the month of July while lady bird beetle, staphylinid beetle and green mirid bug were found most active in the month of August and September in sweeping net sampling and handpicking method.