Dissertation Research: Factors Controlling Larval Survival in the Odonate, Aeshna juncea

控制动物种群分布和数量的因素是生物学家最感兴趣的问题。该项目的目标是确定控制居住在苏必利尔湖岩石海岸线上的蜻蜓幼虫数量的因素。该方法使用了各种技术来检验假说，试图解释蜻蜓的分布和数量。池塘面积小，水质清澈，便于普查种群规模和观察行为互动，对群落的干扰最小。此外，多岩石的海岸线包含大量类似的池塘，因此无需竖起笼子或围栏就可以进行良好复制的野外实验。有几个实验解决了这样的假设，即种群受到食物竞争或大小等级之间的自相残杀的限制。许多池子的温度将被连续测量，以确定是否在夏季或冬季的极端条件下将蜻蜓排除在一些池子之外。将对成年蜻蜓进行监测，以确定幼虫的分布模式是否由产卵偏好决定。该项目的结果将有助于更清楚地了解是什么控制了自然昆虫种群；这些信息对于设计适当的虫害管理和生物防治方案是必要的。

The factors that control the distribution and abundance of animal populations are of fundamental interest to biologists. The goal of this project is to determine the factors controlling a population of dragonfly larvae inhabiting rocky shorelines of Lake Superior. The approach employs a variety of techniques to test hypotheses seeking to explain the distribution and abundance of the dragonflies. The small size and clear water of the pools facilitate censusing population sizes and observing behavioral interactions with minimal disturbance to the community. In addition, the rocky shoreline contains a large number of similar pools, so it is possible to perform well-replicated field experiments without erecting cages or pens. Several experiments address the hypotheses that populations are limited by competition for food or cannibalism between size classes. The temperatures of many pools will be continuously measured to determine if dragonflies are excluded from some pools by extreme conditions in summer or winter. Adult dragonflies will be monitored to determine if patterns of larval distribution are produced by oviposition preferences. The results of this project will help generate a clearer picture of what controls natural insect populations; such information is necessary for designing appropriate programs for pest management and biological control.