棉田棉蚜种群动态及瓢虫对棉蚜种群数量的影响

根据新疆尉犁县4种棉花品种的棉田调查,利用棉蚜数量和时间进行回归分析,探讨其种群动态,应用棉蚜数量和瓢虫数量进行相关分析,研究棉田棉蚜种群与瓢虫种群的关系。结果表明,在不同品种的棉田中,棉蚜种群数量基本呈指数规律上升与下降。在尉犁县孔雀农场的中棉35和军棉1棉田中,从2001年5月31日至6月28日棉蚜种群数量呈指数增长,从6月28日至7月26日棉蚜种群数量呈指数下降。在尉犁县达西村的抗虫棉9和新陆中11棉田中,棉蚜种群数量开始发生和发生高峰期均比中棉35和军棉1推迟1周左右,其中抗虫棉9棉田的棉蚜发生高峰期数量最多,而新陆中11棉田的棉蚜发生期数量最少。在不同品种的棉田中,瓢虫是棉田棉蚜的主要天敌,对棉蚜起控制作用,它与棉蚜种群数量呈显著的跟随关系,发生期比棉蚜滞后1周左右。

Population Dynamics of Cotton Aphids in the Different Cotton Variety Fields and the Effects of Ladybirds on the Population Dynamics of Cotton Aphids

Cotton aphid pests have occurred frequently and seriously since 1987due to the reduction of natural enemies caused by the application of pesticides, which have seriously threatened the cotton production in Xinjiang In this paper, a regressive analysis between the quantity of cotton aphids and the occurring time is carried out based on the investigated data in 4 different cotton variety fields in Yuli County, Xinjiang so as to research the population dynamics of cotton aphids, and the relationship between the populations of cotton aphids and ladybirds in the cotton fields is researched by carrying out a correlation analysis on the quantities of cotton aphids and ladybirds. The results show that the quantity of cotton aphids in the different cotton variety fields increases or decreases exponentially, that is the quantity of cotton aphids in the cotton fields in Kongque Farm, Yuli County, increased exponentially during the period from May 31 to June 28, 2001, but decreased exponentially during the period from June 28 to July 26. The quantity of cotton aphids is different from the different cotton variety fields. Ladybirds are the main natural enemy of cotton aphids, their quantity accords with that of cotton aphids, and their occurring time retards about one week than that of cotton aphids