Onstad D W, Crowder D W, Mitchell P D, Guse C A, Spencer J L, Levine E, Gray M E
Department of Natural Resources and Environmental Sciences, University of Illinois, Urbana, IL 61801, USA.
J Econ Entomol. 2003 Dec;96(6):1872-85. doi: 10.1093/jee/96.6.1872.
Western corn rootworm, Diabrotica virgifera virgifera LeConte, has overcome crop rotation in several areas of the central United States. We expanded a simple model of adult behavior and population genetics to explain how rotation resistance may have developed and to study ways to manage the western corn rootworm in a landscape of corn, soybean, and winter wheat where evolution of resistance may occur. We modeled six alternative management strategies over a 15-yr time horizon, as well as a strategy involving a 2-yr rotation of corn and soybean in 85% of the landscape, to investigate their effectiveness from both a biological and economic perspective. Generally, resistance to crop rotation evolves in fewer than 15 yr, and the rate of evolution increases as the level of rotated landscape (selection pressure) increases. When resistance is recessive, all six alternative strategies were effective at preventing evolution of rotation resistance. The two most successful strategies were the use of transgenic rotated corn in a 2-yr rotation and a 3-yr rotation of corn, soybean, and wheat with unattractive wheat (for oviposition) preceding corn. Results were most sensitive to increases in the initial allele frequency and modifications of the density-dependent survival function. Economically, three alternative strategies were robust solutions to the problem, if technology fees were not too high. Repellant soybean, attractive rotated corn, and transgenic rotated corn, all in 2-yr rotations, were economically valuable approaches. However, even the currently common 2-yr rotation was economical when resistance was recessive and the actual costs of resistance would not be paid until far in the future.
西部玉米根萤叶甲（Diabrotica virgifera virgifera LeConte）已经在美国中部的几个地区克服了作物轮作的防治措施。我们扩展了一个关于成虫行为和种群遗传学的简单模型，以解释抗轮作能力是如何形成的，并研究在玉米、大豆和冬小麦种植区（可能会出现抗性进化）管理西部玉米根萤叶甲的方法。我们在15年的时间跨度内对六种替代管理策略进行了建模，还对一种涉及景观85%区域内玉米和大豆两年轮作的策略进行了建模，以便从生物学和经济学角度研究它们的有效性。一般来说，对作物轮作的抗性在不到15年的时间里就会进化出来，而且随着轮作景观水平（选择压力）的增加，进化速度也会加快。当抗性为隐性时，所有六种替代策略在防止抗轮作能力进化方面都是有效的。最成功的两种策略是在两年轮作中使用转基因轮作玉米，以及玉米、大豆和小麦三年轮作，且在玉米之前种植对产卵无吸引力的小麦。结果对初始等位基因频率的增加和密度依赖生存函数的修改最为敏感。从经济角度来看，如果技术费用不太高，三种替代策略是解决该问题的可靠方案。驱避性大豆、有吸引力的轮作玉米和转基因轮作玉米，均采用两年轮作，都是具有经济价值的方法。然而，即使是目前常见的两年轮作，当抗性为隐性且抗性的实际成本要到很久以后才会产生时，也是经济可行的。
