Host Specificity and Species Richness of Tropical Insect Herbivores in New Guinea: An Outcome of Ecological Factors or Evolutionary History

米勒9707928尽管对雨林保护和管理有着深远的影响，但对以植物为食的热带昆虫的寄主专一性的理解仍然更多的是猜测而不是硬数据。研究人员的方法克服了与先前研究相关的三个主要问题：(1)忽视了实际上不是被研究群落一部分的“暂时性”物种的重要性；(2)没有饲养和观察活昆虫的采样计划不充分；(3)需要在热带地区进行足够的采样工作来“长期”存在。调查人员的方法包括测试活昆虫，以确定它们实际上将以哪些植物为食，允许排除暂住物种，并建立在坚实的基础设施、技术援助以及与巴布亚新几内亚马当附近当地村民发展的关系的基础上。研究人员的具体目标是完成两年前启动的抽样计划，增加15种茜草科和25种桑科植物，然后(1)比较以无关植物科(桑科、大戟科和茜草科)为食的咀叶昆虫的当地区系组成、物种丰富度和寄主专一性；(2)比较所研究的45个咀叶昆虫群落的物种丰度分布；以及(3)探索当地昆虫变量(物种丰富度、寄主专一性和丰度)与当地寄主变量(丰度、产叶模式、其他物理和生物特征)的关系。最大限度地维持昆虫多样性的森林管理和保护战略在很大程度上取决于这种多样性是如何分布的，包括昆虫对特定植物的依赖程度。换句话说，为了维持昆虫群落，必须保留多少寄主植物的多样性？除了明显的保护重要性外，同样的原则也适用于森林病虫害和生防剂的管理。该项目是将分类学专业知识与培训和资源管理相联系，在回答群落生态学和保护生物学的基本问题方面结合起来的一个重要例子。

MILLER 9707928 Despite far reaching implications for rain forest conservation and management, understanding of host specificity of plant-feeding tropical insects remains more of a matter of conjecture than hard data. The investigators' approach overcomes three major problems associated with previous studies: (1) overlooking the importance of "transient" species that are not actually part of the community under study; (2) inadequate sampling programs without rearing and observation of live insects; and (3) need for "long-term" presence in the tropics with sufficient sampling effort. The methodology of the investigators, which includes testing live insects to see what plants they will actually feed on, allows exclusion of transient species and builds on the solid infrastructure, technical assistance and relationships developed with local villagers near Madang, Papua New Guinea. The specific goals of the investigators are to complete the sampling scheme initiated two years ago by adding 15 species of Rubiaceae and 25 additional species of Moraceae, then (1) compare local faunistic composition, species-richness and host specificity of leaf-chewing insects feeding on the unrelated plant families (Moraceae figs , Euphorbiaceae, and Rubicaceae); (2) compare species abundance distribution among the 45 communities of leaf-chewing insects studied; and (3) explore relationships of local insect variables (species richness, host specificity and abundance) to local host variables (abundance, leaf production patterns, other physical and biological characteristics). Forest management and conservation strategies that maximize maintenance of insect diversity depend greatly on how that diversity is distributed, including how dependent the insects are on specific plants. In other words, how much of the host plant diversity must be preserved in order to maintain the insect community? Besides the obvious conservation importance, the same principles extend to management of forest insect pests and biologic al control agents. This project represents a significant example of the integration of taxonomic expertise in answering essential questions in community ecology and conservation biology, with links to training and resource management.