论文部分内容阅读
北京杨锉叶蜂在华北地区杨树苗圃中普遍发生，严重危害黑杨派杨树。在北京地区１ａ发生８～９代，林间以个体群呈聚集分布，以老熟幼虫入土结茧越冬。孤雌生殖后代为雄虫，两性生殖为雌、雄虫。通常雄虫４龄、雌虫５龄。温度影响着北京杨锉叶蜂的羽化及孵化，是种群动态变化的决定因素。在温度适宜及食源充足的状况下，种群保持指数增长，世代差分方程中Ｒ０＝１．４。有效积温为４０００日度。利用病毒、苏云金杆菌及线虫防治，效果分别达９２．９％、１００％、８５．１％。
Populus euphratica, a common species of poplar in North China, is a common occurrence in poplar nurseries in North China. In Beijing area 1a occurred 8 to 9 generations, the forest was aggregated distribution of individual groups to mature larvae cocoon into the soil overwintering. Parthenogenesis offspring male, male and female reproductive sex. Usually 4 years old male, female 5 years old. Temperature affects the eclosion and hatch of Populus euphratica in Beijing, which is the determinant of the population dynamics. Under appropriate conditions of temperature and adequate food supply, the population kept exponential growth, R0 = 1.4 in the generational difference equation. Effective accumulated temperature of 4000 days. The use of viruses, Bacillus thuringiensis and nematode control, the results were 92.9%, 100%, 85.1%.