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

9701122 Gotelli 这项研究的重点是蚁狮 Myrmeleon immaculatus 体型的地理差异。 蚁狮是美国东部和南部常见的幼虫昆虫。它们的幼虫寿命为 1 至 3 年，是节肢动物的有效捕食者。 从俄克拉荷马州到纽约的 37 个种群的幼虫收集结果表明，M. immaculatus 的体型随着纬度的增加而增大：北方蚁狮比南方蚁狮更大。 这项研究探讨了这种模式是由于先天还是后天造成的。 换句话说，蚁狮体型的变化是由于遗传还是环境的影响？ 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。 该实验消除了环境影响并揭示了生长的遗传决定因素。 为了补充这项研究，幼虫将在俄克拉荷马州和康涅狄格州之间的相互移植实验中在田间饲养。这两个实验的结果将揭示蚁狮的生长速度和成年体型主要是由个体基因决定还是由它们的饲养环境决定。 其他可能影响不同纬度昆虫体型大小的因素包括温度、猎物丰度和分布。 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。 猎物的体型大小将通过在佐治亚州和佛蒙特州之间 25 个不同地点设置陷阱来确定。 这些数据将揭示蚁狮的身体大小与猎物的身体大小和丰度之间是否存在相关性。 这项研究将增强我们对体型的环境和遗传组成部分的理解，并揭示大地理范围内生命史变异的本质。

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.