杭州郊区菜蚜种群的空间动态

Spatial dynamics of vegetable aphid population in suburbs of Hangzhou.

利用 1 990～ 1 992年杭州郊区菜区 1 0茬结球甘蓝、2 3茬小白菜上菜蚜种群的系统调查数据 ,选择受密度影响较小的负二项分布的K值 ,描述了菜蚜混生种群的空间格局及其时序动态 .2类蔬菜上桃蚜、萝卜蚜混生种群终年呈聚集分布 ,但聚集强度变化有明显的季节规律 .7～ 9月聚集度最高 ,5和 1 1月前后有 2个明显的扩散高峰 .在甘蓝作物上的聚集强度随时间的变化过程因季节而异 ,春夏季为高 低 高 ,夏秋季一直较高 ,秋冬季在年间有较大变化 ,冬春季开始由低向高变化 ,随后上下波动 .萝卜蚜的聚集度较桃蚜为高 .综合了菜蚜混生种群的数量消长规律、环境因子的变化等信息 ,对其空间图式及其时序动态特征的成因进行了讨论 .

Systematic investigations on vegetable aphid population were carried out on 10 crops of Brassica oleracea var.capitata and 23 crops of B.campestris ssp.chinensis during 1990～1992 in the suburbs of Hangzhou.The K value of negative binomial distribution less affected by density was chosen to describe the spatial and temporal patterns of mixed aphid population. The results indicated that the mixed population of Myzus persicae and ipaphis erysimi was aggregated on the two vegetables throughout the year, but the aggregation intensity changed seasonally. The population was highly aggregated from July to September, and two peaks of dispersal was shown on May and November. The intensity of aggregation on Brassica oleracea var. capitata differed between seasons. From spring to summer, the population changed from highly to loosely aggregated, and then, to highly aggregated again, but from summer to autumn, the aggregation intensity was always very high. The temporal pattern of aggregation from autumn to winter differed between years, and the intensity of aggregation increased gradually, and then, fluctuated from winter to spring.The aggregation intensity of L.erysimi was higher than that of M.persicae. With reference to the trade-off of population and the change of environmental factors, the mechanism of the observed spatial patterns was discussed.