江西省烟田主要害虫及其天敌种群动态

通过采用5点调查法，对江西省南昌市烟田主要害虫及其天敌种群数量进行调查并对其进行动态分析。结果显示：烟蚜在烟草整个生长期均有发生，其种群数量动态变化呈双峰曲线，第1个蚜量高峰期出现在6月初。第2个蚜量高峰期出现在6月末至7月初，且蚜量雨后显著降低，雨后高温则又明显增加。烟青虫和斑须蝽在5月初开始发生，其种群数量动态变化均呈单峰曲线。烟青虫虫量高峰期出现在5月末至6月初，斑须蝽虫量高峰期则在6月中旬。烟田内主要天敌有烟蚜茧蜂、蜘蛛类、瓢虫和草蛉。天敌与烟蚜、烟青虫具一定的虫量跟随关系，其中烟蚜茧蜂和草蛉分别在烟草生长前后期与烟蚜跟随关系明显，蜘蛛则在烟青虫发生后与其跟随关系较为明显。

Population Dynamics of the Main Pests and Natural Enemies in Tobacco Fields in Jiangxi Province

Based on the survey method of five points, we investigated into the population of the pests and natural enemies in tobacco fields in Nanchang, Jiangxi Province, and analyzed their dynamic changes. The experimental results indicated that the population of Myzuspersicae had two peaks within a year, the first in early June, and the second from the end of June to early July. Also the population ofM. persicae decreased significantly after the rain, and then increased significantly after high temperature. The population of Helicoverpa assulta and Dolycoris baccarum, respectively, had one peak within a year. The peak of H. assulta population occurred from the end of May to early June, and the peak of D. baccarum population occurred in the middle of June. The main natural enemies of the pests in tobacco fields included Aphidius gifuensis, spiders, lacewings and lady beetles. These natural enemies showed synchronization with M. persicae and H. assulta. Of the natural enemies, A. gifuensis and lady beetles, respectively, showed obvious synchronization with M. persicae at the early or later period of the tobacco growth, and spiders showed obvious synchronization with H. assulta after its occurrence.