杭州郊区菜蚜种群的数量消长规律

Population fluctuation of aphids on crucifer vegetables in Hangzhou suburbs.

对杭州郊区菜蚜的数量消长规律进行了连续多年的系统调查 .结果表明 ,在杭州郊区十字花科蔬菜上发生的菜蚜只有桃蚜 (Myzuspersicae)和萝卜蚜 (Lipaphiserysimi) .2种菜蚜混生种群的数量消长 1年中有 2个明显的高峰 ,分别出现在 5～ 6月和 1 1月前后 ;一般年份高峰期田间虫量可达平均每株 50 0头以上 ,且第 2个高峰虫量较高 ,持续时间较长 .在夏末秋初气温明显偏低的年份 ,8～ 9月作物上虫量上升迅速 ,最高也可达平均每株上千头的水平 .盛夏和隆冬季节数量都很低 .每年的 1 2月至次年的 5月以桃蚜占绝对优势 ,7～ 1 0月以萝卜蚜占绝对优势 ,而 5～ 7月和 1 0～ 1 2月则 2种蚜虫的发生比例交错变换 .温度是决定菜蚜混生种群数量消长规律和导致 2种蚜虫季节消长规律差异的一个主要因子 .文中对食料、天敌等因子的作用也做了讨论 .

Many years observations on the patterns of population fluctuation of aphids on crucifer vegetables in Hangzhou suburbs show that only two species of aphids, Myzus persicae and Lipaphis erysimi occurred on crucifer vegetables. The mixed populations of the two aphids showed two peaks each year, with the first one from May to June and the second one around November. The average population density in the two peaks usually reached over 500 aphids per plant, and the second peak usually exceeded the first one in both density and duration. However, in years with low temperature in late summer and early autumn, the aphid population density rapidly increased from August to September and reached over 1000 aphids per plant in peak period, and was very low in both midsummer and midwinter. M.persicae was predominant from December to May of the following year, L.erysimi was predominant from July to October, and their relative predominance was alternated each year from May to July and from October to December, respectively. Temperature is a key factor affecting the seasonal fluctuation pattern of the mixed population of the two aphids and their interspecific difference in seasonal fluctuation. The influence of other factors such as plant nutrition and natural enemies was also discussed.