Li Minlong, Yang Long, Jia Shuangshuang, Kang Shuyuan, Yang Yizhong, Lu Yanhui
College of Plant Protection, Yangzhou University, Yangzhou, China.
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
Pest Manag Sci. 2025 Feb;81(2):689-697. doi: 10.1002/ps.8467. Epub 2024 Oct 8.
Cotton bollworm, Helicoverpa armigera (Hübner), threatens many crops. Bacillus thuringiensis (Bt) cotton has been planted to control this severe pest in northern Xinjiang, China. In 2021 and 2022, we monitored the activity densities of H. armigera males using sex pheromone traps in Bt cotton and non-Bt maize fields. We assessed how much of the population variation of cotton bollworm in the fields within the Bt cotton planting area could be explained by (i) landscape composition [including the proportion of Bt cotton among total area of host crops (cotton, maize, wheat and vegetables)], (ii) landscape configuration (patch density - i.e. the number of patches within a given area) across 0.5-2.0 km scales, or (iii) the population density of the previous pest generation.
Cotton bollworm activity-density exhibited two distinct peaks annually (mid- to late May and mid-July each year), with the number of males caught during the second peak significantly and positively correlated with the first peak's numbers. The suppressive effect of the proportion of Bt cotton in the landscape on bollworms was more pronounced at larger scales, and patch density had a significant positive effect on bollworm activity density.
These findings support (i) the promotion of Bt cotton in northwestern China has reduced and suppressed the occurrence of cotton bollworms at the landscape scale and (ii) the importance of controlling spring populations for effective summer outbreak management, and (iii) that cotton bollworm control should be coordinated at a large scale across multiple crop fields. © 2024 Society of Chemical Industry.
棉铃虫（Helicoverpa armigera (Hübner)）对多种作物构成威胁。在中国新疆北部，已种植苏云金芽孢杆菌（Bt）棉花以防治这种严重害虫。在2021年和2022年，我们使用性诱捕器监测了Bt棉田和非Bt玉米田中棉铃虫雄虫的活动密度。我们评估了Bt棉种植区内田间棉铃虫种群变异的多大比例可由以下因素解释：（i）景观组成[包括Bt棉在寄主作物（棉花、玉米、小麦和蔬菜）总面积中的比例]，（ii）0.5 - 2.0千米尺度上的景观配置（斑块密度，即给定区域内的斑块数量），或（iii）前一代害虫的种群密度。
棉铃虫活动密度每年呈现两个明显峰值（每年5月中旬至下旬和7月中旬），第二个峰值期间捕获的雄虫数量与第一个峰值的数量显著正相关。景观中Bt棉比例对棉铃虫的抑制作用在较大尺度上更为明显，斑块密度对棉铃虫活动密度有显著的正向影响。
这些发现支持以下观点：（i）中国西北部推广Bt棉花已在景观尺度上减少并抑制了棉铃虫的发生；（ii）控制春季种群对于有效管理夏季爆发的重要性；（iii）棉铃虫防治应在多个作物田的大尺度上进行协调。© 2024化学工业协会。
