Niche Diversification and Coexistence of Insect Herbivores along the Food Quality Axis: Do Grasshoppers Ride the Rails?

基于功能营养生态学的新进展，这项研究解决了中心问题：如何重要的是食品质量和可用性，以确定共存的昆虫食草物种的数量，组成和相对丰度？主要营养质量（蛋白质和碳水化合物水平）的重要性，昆虫草食动物的性能差异很大，在自然发生的食品植物，和物种的反应，可变的食物供应量不同。利用控制饲养研究，对有利于某些物种的营养条件进行精确预测，以预测物种的共存和相对丰度。研究重点是蝗虫，这是丰富的，多样的，功能重要，经济上重要的食草昆虫在大多数草地上发现。 对于蛋白质：碳水化合物比例不同的食物，将确定支持最佳性能（“均衡饮食”）、次优饮食性能以及常见蝗虫物种调节营养摄入以实现均衡饮食的能力的营养摄入目标。由于天然食用植物的叶子质量通常对蚱蜢来说并不是最佳的，因此产生的分析框架将预测蚱蜢如何用次优食物来应对不断变化的环境--典型情况。 将在自然变化的条件下测试以营养为基础的理论预测蝗虫群落中物种丰度和共存模式的能力。

Based on new advances in functional nutritional ecology, this study addresses the central question: How important is food quality and availability for determining the number, composition and relative abundances of coexisting insect herbivore species? Primary nutritional quality (protein and carbohydrate levels) important to insect herbivore performance varies greatly in naturally occurring food plants, and species responses to variable food availability differ. Using controlled feeding studies, exact predictions about nutritional conditions that favor some species over others will be devised to predict coexistence and relative abundances of species. Research focuses on grasshoppers, which are abundant, diverse, functionally significant, and economically important insect herbivores found in most grassland. Nutritional intake targets supporting optimal performance ("balanced diets"), performance on suboptimal diets, and capacities of common grasshopper species to regulate nutritional intake to achieve balanced diets will be determined for food that varies in the ratio of protein:carbohydrate. Because leaf quality of naturally occurring food plants is not typically optimal to grasshoppers, the resulting analytical framework will predict how grasshoppers can respond to changing environments with suboptimal food - the typical situation. The ability of nutrition-based theory to predict patterns of species abundance and coexistence in grasshopper communities will be tested under naturally varying conditions.