Dissertation Research: Geographic Variation in Life History Traits of Myrmeleon immaculatus

9701122戈泰利这项研究的重点是蚂蚁狮子Myrmeleon immaculatus身体大小的地理变化。蚂蚁狮子是美国东部和南部常见的幼虫。它们作为幼虫可以活1到3年，是节肢动物上有效的坐等捕食者。采集了从俄克拉何马州到纽约的37个种群的幼虫，结果表明，无斑纹夜蛾的体型随着纬度的增加而增加：北部蚂蚁狮子比南部蚂蚁狮子大。这项研究解决了这种模式是否源于先天还是后天的问题。换句话说，蚂蚁狮子的体型变化是由于遗传或环境影响吗？这个问题将通过在环境控制的生长室中饲养一龄幼虫来回答。这个实验消除了环境的影响，揭示了生长的遗传决定因素。为了补充这项研究，幼虫将在俄克拉何马州和康涅狄格州之间的相互移植实验中进行野外饲养。这两个实验的结果将揭示蚂蚁狮子的生长速度和成年身体大小主要是由个体基因还是由它们生长的环境决定的。其他可能影响不同纬度昆虫身体大小的因素是温度和猎物的丰度和分布。将通过在不同温度和食物水平下饲养北方和南方种群的幼虫来测试食物和温度对生长速度的影响。猎物的身体大小将通过在佐治亚州和佛蒙特州之间的25个不同地点进行陷阱诱捕来确定。这些数据将揭示蚂蚁狮子的身体大小和猎物的身体大小和丰度之间是否存在关联。这项研究将加深我们对身体大小的环境和遗传成分的理解，并揭示大地理范围内生活史变异的本质。

9701122 Gotelli This research focuses on geographic variation in body size of the ant lion, Myrmeleon immaculatus. Ant lions are larval insects common throughout the eastern and southern United States. They live for 1 to 3 years as larvae, and are effective sit-and-wait predators on arthropods. Collections of larvae from 37 populations, ranging from Oklahoma to New York, revealed that M. immaculatus body size increased with latitude: northern ant lions were larger than southern ant lionq. This research addresses whether this pattern is due to nature versus nurture. In other words, is ant lion body size variation due to genetic or environmental influences? This question will be answered by raising first-instar larvae in environmentally controlled growth chambers. This experiment removes environmental influences and reveals genetic determinants of growth. To complement this study, larvae will be reared in the field in a reciprocal transplant experiment between sites in Oklahoma and Connecticut. The results from these two experiments will reveal whether growth rates and adult body size of ant lions are determined primarily by individuals genes or by the environment in which they are raised. Other factors that may influence insect body size at different latitudes are temperature and prey abundance and distribution. The effects of food and temperature on growth rate will be tested by raising larvae from northern and southern populations at different temperatures and food levels. Prey body sizes will be determined by pitfall-trapping at 25 different sites between Georgia and Vermont. These data will reveal whether there is a correlation between ant lion body size and prey body size and abundance. This study will enhance our understanding of the environmental and genetic components of body size, and reveal the nature of life history variation on a large geographic scale.