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

9974067舒尔茨这个LTREB项目将继续调查一片受到吉普赛飞蛾反复爆发影响的森林。吉普赛飞蛾是一种侵袭性森林害虫的典型例子，在美国东部是一个主要的经济问题，它周期性地使数百万公顷的落叶林落叶。造成这种种群动态的因素尚不清楚，并构成了种群生物学和虫害防治工作的中心焦点。以前的工作已经确定了吉普赛蛾诱导树叶化学变化的能力，以及这些变化对一种可以影响吉普赛蛾种群增长的病毒的抑制影响，这可能是决定吉普赛蛾种群周期的重要机制。在这个LTREB项目中，将检验两个长期假说：(1)吉普赛蛾在暴发初期引起的橡树叶化学成分的变化增加了毛虫对杆状病毒的抵抗力，促进了吉普赛蛾种群的增长，(2)吉普赛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，吉普赛蛾的数量正在如预期的那样增加，以应对即将爆发的疫情，而且落叶和叶片化学正在发生一致的变化。与核心长期监测相关的实验研究表明了树木变化的一些机制，并将这些机制与飞蛾种群动态联系起来。这项研究将为了解吉普赛飞蛾的动态以及寄主植物和相关草食动物如何应对一种重要的经济害虫物种的周期性暴发提供有价值的了解。

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.