Dissertation Research: Evolution of the True Cutworms (Lepidoptera: Noctuidae) Inferred from Nuclear Genes

9623799当代昆虫物种和它们赖以生存的植物之间的Mitter相互作用受到它们共同的历史关系的强烈影响，这表明系统学(物种谱系)在解释寄主植物的使用模式方面发挥了重要作用。最近关于夜蛾科(约25,000种)的系统发育的研究表明，可能存在一个“真正的地老虎”谱系，它将来自四个传统亚科的大约8,000种物种组合成一个大的亚科，即夜蛾亚科。与大多数其他夜蛾不同，夜蛾亚科通常(尽管并不总是)拥有“神秘”的毛虫(颜色不明显，不易观察)，并以非木本植物为食。大多数情况下，这些毛虫有广泛的食用植物偏好，而且经常是害虫。在这项研究中，博士生安德鲁·米切尔在查尔斯·米特和杰罗姆·雷杰的指导下，将利用两个核基因的DNA序列来更关键地评估夜蛾亚科昆虫之间的系统发育关系。Mitchell、Mitter和Regier将分析来自50个物种的延伸因子-1α(EF-1a)和多巴脱羧酶(DDC)DNA序列，这些物种代表亚科内的所有主要亚组(部落和亚族)，以确定这些组的界限并估计这些组之间的关系。然后，系统发育将被用来确定在地老虎蛾群体的漫长历史中，物种何时采用了不同的地理分布、取食方式和饮食偏好。特别是，这些研究应该有助于确定具有这些特征的物种是密切相关的，还是只有遥远的亲缘关系。了解地老虎蛾的这一基本生物学知识可能有助于管理害虫物种。

9623799 MITTER Interactions among contemporary insect species and the plants they feed on are strongly influenced by their shared historical relationships, suggesting an important role for phylogenies (genealogies of species) in explaining patterns of hostplant use. Recent work on the phylogeny of the huge moth family Noctuidae (about 25,000 species), previously poorly understood, indicates that a "true cutworm" lineage may exist, which combines approximately 8,000 species from four traditional subfamilies into a single large subfamily, the Noctuinae. Unlike most other noctuids, Noctuinae typically (though not invariably) possess caterpillars that are "cryptic" (inconspicuously colored, not easy to observe) and feed on non-woody plants. Most often, these caterpillars have broad food plant preferences, and frequently they are pests. In this research, doctoral student Andrew Mitchell, under the direction of Charles Mitter and Jerome Regier, will use the DNA sequences of two nuclear genes to more critically assess the phylogenetic relationships among the insects in the Noctuinae. Mitchell, Mitter and Regier will analyze Elongation Factor-1 alpha (EF-1a) and Dopa Decarboxylase (DDC) DNA sequences from 50 species, representing all major subgroups (tribes and subtribes) within the subfamily, to define the limits of and estimate the relationships among these groups. The phylogeny will then be used to determine when, over the long history of the cutworm moth group, species have adopted different geographic distributions, modes of feeding and diet preferences. In particular, the studies should help determine whether species that share any of these features are closely, or only distantly, related. Knowledge of this basic biology of the cutworm moths may assist efforts to manage pest species.