转基因抗虫棉种植面积变化对花生田棉铃虫种群影响

【目的】棉铃虫Helicoverpa armigera(Hübner)是花生田主要害虫之一。转基因抗虫棉全面推广后,棉铃虫种群(包括棉田、花生田、玉米田)得到有效控制。近年,随着转基因抗虫棉种植面积逐年下降,花生田棉铃虫种群呈现逐年上升趋势。【方法】本文通过调查山东省花生主产区(非棉区)龙口、招远、莱阳、文登四个县级市花生田棉铃虫成虫、卵量、幼虫量等的发生情况,分析了棉铃虫发生面积及种群数量15年(2000—2014年)的变化规律,并重点分析了主要影响因素。【结果】结果表明:花生棉铃虫发生面积受棉花种植面积影响较大,二者呈显著负相关性;花生田棉铃虫累计诱蛾量总体呈下降趋势,但与棉花种植面积相关性不显著;棉铃虫卵量、虫量与抗虫棉种植面积呈显著负相关性。【结论】所以,转基因抗虫棉种植面积减少是导致花生田棉铃虫种群数量上升的主要因素。另外,近年玉米田棉铃虫发生面积也呈逐年上升趋势,与抗虫棉种植面积呈显著负相关。所以,随转基因抗虫棉种植面积的下降,若不采取有效措施,棉铃虫种群可能会出现大发生趋势。

Impact of Bt cotton plantations on cotton bollworm populations in peanut fields

Objectives] The cotton bollworm, Helicoverpa armigera (Hübner), is one of main pests of peanut crops in Shandong Province. The widespread planting of Bt cotton at the end of 1990’s has effectively controlled the cotton bollworm in peanut fields. However, as planting of Bt cotton has gradually decreased in recent years, cotton bollworm populations in peanut fields are once again rising yearly. Methods] Numbers of adults, eggs and larvae of H. armigera in peanut fields in four county-level cities (Longkou, Zhaoyuan, Laiyang and Wendeng where no Bt cotton is planted), were monitored and trends in the cotton bollworm population between 2000 and 2014 analyzed. Results] There is a significant negative correlation between the area planted in Bt cotton and the occurrence of cotton bollworms in peanut fields, and between the area of Bt cotton and the amount of cotton bollworm eggs and larvae. Conclusion] Reduction in the planting of transgenic cotton is a major factor contributing to the increase in cotton bollworms in peanut fields. In addition, with the decline in planting of Bt cotton, the area infested by cotton bollworms in corn and peanut fields has increased yearly. If no effective measures are taken, there may be future outbreaks of the cotton bollworm.