论文部分内容阅读
1992年一代棉铃虫在我县麦田暴发成灾,发生面积之大,虫量之高,危害损失之重,为历史罕见。其暴发特点及暴发原因分析如下:一、暴发特点1.发生早,来势猛,虫量高5月20日在麦田调查,幼虫为2—3龄,最高4龄,发生期比历年提前5—7天,5月22日调查,幼虫为3—5龄平均平方米有虫6.8头,最高达26头,折亩存虫量4532.9头,为12年同期的18.54倍。5月28日调查,平均一平方米有虫10.7头,最高达58头,折亩存虫量7132.6头,是大发生的1989年同期虫量的6.99倍,部分地块一亩高达1—1.32万头。
The first generation of cotton bollworm in 1992, the outbreak of wheat fields in our county plagued, the occurrence of large area, the amount of insects, the damage of the weight of heavy, rare in history. The characteristics of the outbreak and the reasons for the outbreak are as follows: First, the characteristics of the outbreak 1. The occurrence of early, fierce trend, insect high May 20 investigation in the wheat field, the larvae 2-3 years old, up to 4 years old, 7 days, May 22 survey larvae 3-5 years average square meter insect 6.8, up to 26, fold the amount of insect pests 4532.9, 18.54 times the same period for 12 years. May 28 survey, an average of 10.7 square meters per square meter, up to 58, fold the amount of insect stock 7132.6, is the largest occurrence of 6.99 times the amount of 1989, the amount of some plots of up to 1-1.32 acres Ten thousand.