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

当代昆虫物种与其所食植物之间的相互作用受到它们共同的历史关系的强烈影响，这表明系统发育学（物种谱系学）在解释寄主植物利用模式方面起着重要作用。最近对夜蛾科（约25000种）的系统发育的研究表明，可能存在一个“真正的夜蛾”谱系，它将来自四个传统亚科的大约8000种物种合并为一个大亚科，即夜蛾科。与大多数其他夜蛾不同，夜蛾科通常（尽管并非总是）拥有“隐蔽”的毛毛虫（颜色不明显，不易观察），以非木本植物为食。大多数情况下，这些毛毛虫对食物有广泛的偏好，而且它们经常是害虫。在这项研究中，博士生Andrew Mitchell在Charles Mitter和Jerome Regier的指导下，将使用两个核基因的DNA序列来更严格地评估夜蚊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-1 α (EF-1a)和多巴脱羧酶（DDC） DNA序列，代表亚科内所有主要亚群（部落和亚部落），以确定这些群体之间的界限并估计这些群体之间的关系。然后，系统发育将被用来确定，在漫长的历史中，在什么时候，各个物种采用了不同的地理分布、摄食模式和饮食偏好。特别是，这些研究应该有助于确定具有这些特征的物种是近亲还是远亲。了解这些蛾类的基本生物学知识可能有助于控制害虫种类。

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.