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1998年在河南安阳植棉区对麦套春棉和平作春棉两种类型棉田二、三代棉铃虫自然种群进行了系统观测 ,并组建了相应的生命表。麦套春棉和平作春棉二代棉铃虫世代存活率分别为0 .0 92 %和 0 .1 0 5% ,均低于相应的三代 (分别为0 .465%和 0 .450 % )。麦套春棉和平作春棉二代棉铃虫自然种群趋势指数 I分别为 0 .2 946和0 .3376,均低于相应的三代 (分别为 2 .91 2 3和2 .831 8)。麦套春棉二代棉铃虫世代存活率和种群趋势指数均低于同代的平作春棉 ,而麦套春棉三代棉铃虫世代存活率和种群趋势指数则高于同代的平作春棉。天敌捕食和气候因子是影响两类棉田二、三代棉铃虫自然种群数量变动的关键因素。麦套春棉二代棉铃虫发生期 ,捕食性天敌发生量较大 ,棉铃虫自然种群数量较平作春棉减少幅度大 ;平作春棉三代棉铃虫发生期 ,棉铃虫自然种群数量较麦套春棉田减少幅度大
In 1998, the natural populations of cotton bollworms of the second and third generations of two types of cotton fields were surveyed and the corresponding life tables were established in the cotton planting area of Anyang in Henan Province. The surviving rates of the second generation of cotton bollworm with spring wheat and spring cotton were 0. 092% and 0. 0 05%, respectively, which were lower than the corresponding 3rd generation (0.455% and 0.45% respectively). The trend index I of natural population of cotton bollworm, which is the second generation cotton of spring wheat and wheat, was lower than that of the corresponding three generations (0.91 and 3.83 1, respectively). The second generation cotton bollworm wheat sheath generation survival rate and population trend index were lower than those of the same generation of spring cotton, and the third generation wheat straw spring cotton bollworm generation survival rate and population trend index was higher than the same generation of Ping spring cotton. Predation of predators and climatic factors are the key factors affecting the natural populations of two and three generations of cotton bollworms in two types of cotton fields. During the occurrence of cotton bollworm, the second generation of cotton bollworm, the occurrence of predatory natural enemies was larger, and the natural population of H. armigera was reduced more than that of flat cotton. The third generation of cotton bollworm, Reduction of cotton fields