LTREB: Long-term Study of a Gypsy Moth-impacted Forest

9974067 schultzltreb项目将继续调查受舞毒蛾反复爆发影响的森林。舞毒蛾是入侵森林害虫的典型例子，是美国东部的一个主要经济问题，它定期使数百万公顷的落叶林落叶。导致这种种群动态的因素仍然未知，并且构成了种群生物学和害虫防治工作的中心焦点。先前的工作已经确定了舞毒蛾诱导树叶化学变化的能力，以及这些变化对影响舞毒蛾种群生长的病毒的抑制作用，这可能是决定舞毒蛾种群周期的重要机制。在这个LTREB项目中，将测试两个长期假设：(1)在爆发初期，舞毒蛾引起的橡树叶化学变化增加了毛虫对杆状病毒的抵抗力，促进了舞毒蛾种群的增长；(2)舞毒蛾的落叶对其群落中一系列共存的食草动物有直接和间接的影响。到目前为止的结果表明，舞毒蛾的数量正在增加，正如预期的那样，即将爆发，落叶和叶子的化学成分正在同步变化。与核心长期监测相关的实验研究表明，树木变化涉及一些机制，并将这些机制与蛾类种群动态联系起来。这项研究将提供有价值的了解舞毒蛾的动态，以及寄主植物和相关食草动物如何应对周期性爆发的重要经济害虫物种。

9974067SchultzThis LTREB project will continue to investigate a forest that has been influenced by repeated gypsy moth outbreaks. The gypsy moth is a classic example of an irruptive forest pest, and is a major economic problem in the eastern US where it periodically defoliates millions of hectares of deciduous forest. Factors that contribute to this kind of population dynamic remain unknown, and comprise a central focus of both population biology and pest control efforts. Previous work has identified the ability of the gypsy moth to induce changes in tree leaf chemistry, and the inhibitory impact of those changes on a virus that can influence gypsy moth population growth, as likely important mechanisms determining gypsy moth population cycles. In this LTREB project, two long-term hypotheses will be tested: (1) Gypsy moth-induced changes in oak leaf chemistry during incipient outbreak increases caterpillar resistance to a baculovirus, promoting gypsy moth population growth, and (2) gypsy moth defoliation has direct and indirect impacts on a range of coexisting herbivores in its community. Results thus far indicate that gypsy moth numbers are increasing as expected for an impending outbreak, and that defoliation and leaf chemistry are changing in concert. Experimental studies linked to the core long-term monitoring suggest some of the mechanisms involved in tree changes and link these to moth population dynamics. This study will provide valuable understanding of the dynamics of gypsy moth, and how the host plant and associated herbivores respond to periodic outbreaks of an economically important pest species.