Department of Crop and Soil Sciences, A364 Plant and Soil Science Bldg., Michigan State University, East Lassing, MI 48824, USA.
J Econ Entomol. 2011 Aug;104(4):1357-63. doi: 10.1603/ec10414.
Since the discovery of the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), in North America in 2000, chemical control has been the most effective method to manage aphid outbreaks. Increased insecticide use in soybean raises the possibility of developing insecticide resistance in soybean aphid, and monitoring insecticide susceptibility is essential to maintain pesticide tools. We developed a simple and reliable aphid-dip bioassay by using a tea strainer that resulted in -90% survival in controls. Using this technique, we tested susceptibility of a greenhouse strain of soybean aphid that has never been exposed to insecticides, and field-collected aphid strains from two counties in Michigan. Aphid susceptibility was tested for five insecticides by dipping groups of five aphids in each insecticide dose for 10 s. After 48 h, aphids were classified as dead or alive, and counted. Aphids from all strains were highly susceptible to chlorpyrifos, lambda-cyhalothrin, esfenvalerate, and dimethoate, with LC50 and LC90 values well below the recommended application rates. However, aphids showed less susceptibility after 48 h to neonicotinoid imidacloprid, with higher LC90s and wider fiducial limits. This illustrated the potential limitation of using a 48-h assay to evaluate insecticides with longer-term, sublethal impacts. Nevertheless, this study made use of a simple aphid-dip method to test and compare insecticide susceptibility of soybean aphid. In the event of a field failure, the aphid populations involved can be tested in comparison to a susceptible greenhouse strain to determine the extent of resistance development.
自 2000 年在北美洲发现大豆蚜（Aphis glycines Matsumura）以来，化学防治一直是管理蚜虫暴发的最有效方法。大豆杀虫剂的使用增加增加了大豆蚜产生抗药性的可能性，监测杀虫剂敏感性对于维持农药工具至关重要。我们开发了一种简单可靠的蚜虫浸洗生物测定法，使用茶漏可使对照中的蚜虫存活率达到-90%。使用这种技术，我们测试了从未接触过杀虫剂的温室大豆蚜种群以及密歇根州两个县田间采集的蚜虫种群的敏感性。通过将每组 5 只蚜虫浸入每种杀虫剂剂量中 10 秒来测试 5 种杀虫剂的敏感性。48 小时后，将蚜虫分为死亡或存活，并进行计数。所有品系的蚜虫对毒死蜱、氯氟氰菊酯、乙氰菊酯和乐果高度敏感，LC50 和 LC90 值远低于推荐的施用量。然而，48 小时后，蚜虫对新烟碱类杀虫剂噻虫啉的敏感性降低，LC90 更高，置信区间更宽。这说明了使用 48 小时测定法评估具有长期、亚致死影响的杀虫剂的潜在局限性。然而，本研究利用了一种简单的蚜虫浸洗方法来测试和比较大豆蚜的杀虫剂敏感性。在田间失效的情况下，可以将涉及的蚜虫种群与敏感的温室种群进行比较，以确定抗药性发展的程度。
