论文部分内容阅读
本文比较研究了北方棉区平作和麦套春棉治虫与不治虫共四种类型棉田的棉铃虫及其优势天敌的种群动态。结果表明，二代棉铃虫发生期平作春棉的始卵期较麦套春棉提早３～５ｄ，四代棉铃虫发生期后者的终卵期较前者推迟１０～１５ｄ；与常规治虫相比，平作春棉和麦套春杯不治虫的百株累计总卵量分别增加了１５１．４％和１６０．７％，百株累计总幼虫量则分别增加了２０５．１％和２８０．８％。与常规治虫相比，平作春棉不治虫二、三、四代棉铃虫卵及幼虫的平均寄生率分别增加了２００．０％、１１０．０％和６７５．０％及１４８．０％、２４７．５％和８．５％，麦套春棉则增加了３６，１％，３８．９％和９５．８％及６４．４％、３６９．０％和３１．６％；无论哪种类型的棉田，棉铃虫优势捕食性天敌的百株累计量均呈逐代上升的趋势。
In this paper, population dynamics of cotton bollworm (Helicoverpa armigera) and its dominant natural enemies in four types of cotton fields in the northern cotton paddy crop and wheat sheathworm were compared. The results showed that the onset period of second generation cotton bollworm plain cotton was earlier than that of wheat straw spring cotton three to five days earlier, the fourth generation cotton bollworm latter period of the latter part of the latter is 10-15 days later than the former; , The cumulative total number of eggs in spring cotton cup and wheat spring cup did not increase by 151.4% and 160.7%, respectively, and the cumulative total larvae in one strain increased by 205.1% and 280.8% respectively . Compared with the conventional pest control, the average parasitism rates of cotton bollworm eggs and larvae increased by 200.0%, 110.0%, 675.0% and 148.0% respectively for the second, third and fourth generation of pest insects, and 247 .5% and 8.5%, wheat straw spring cotton increased by 36,1%, 38.9% and 95.8% and 64.4%, 369.0% and 31.6%; no matter what type Cotton bollworm, the predominant predators of cotton bollworm cumulative one hundred strains showed an upward trend from generation to generation.