稻苞虫是我区水稻主要害虫。近几年来由偶发性扩展为常发性害虫。1974年全区发生12万亩,1975年23万亩,1976年扩大到28万亩,1977年发生面积虽比1976年减少2万亩,局部地区为害损失仍相当严重。据勉县东风公社柳营大队科研站测定,防治的亩产稻谷819斤,未防治的仅606斤,减产29%。宁强县病虫测报站测定,每丛水稻有4头幼虫,损失稻谷39.3%, Rice shell insects is the main rice pests in our area. In recent years, the sporadic expansion from a pest. In 1974, the entire region took up 120,000 mu, 230,000 mu in 1975 and 28,000 mu in 1976. Although the area was reduced by 2 million mu in 1977 compared with 1976, losses in some areas are still quite serious. According to Mianxian Dongfeng commune Liuying Battalion research station determination, prevention and control of 819 kg of mu of rice, not only prevention and control of 606 kg, a reduction of 29%. Ningqiang County Pest Reporter determined that there were 4 larvae per bundle of rice, which lost 39.3% of rice,