| This thesis is an investigation of the application of DNA barcoding in improving the taxonomy and systematics of Lepidoptera. I present case studies to demonstrate the use of DNA barcoding as a powerful tool in species discovery, in identification of immature stages, for refining historically problematic taxonomy in various groups of Lepidoptera, in regional biodiversity surveys, and in inferring phylogenies alongside other mitochondrial and nuclear markers. In chapter one, I follow the traditional methodology using genital morphology to describe 25. new species of Nearctic Coleophora discovered through DNA barcoding. In Chapter Two I refine the disputed taxonomy of Melanargia, a widely distributed Palaearctic genus with closely related but highly variable species, using new data from DNA barcodes and two other genes. In Chapter Three, I present the first phylogenetic hypothesis for the Afrotropical-Oriental genus Colotis, inferred from three mitochondrial and nuclear genes alongside DNA barcodes, and address questions on historical biogeography and species-level taxonomy that arose during this work. In Chapter Four, my study of a poorly known Lepidoptera fauna - the Gnorimoschemini of the Yukon - using DNA barcoding revealed a surprising diversity (21 species in 3 genera) for the region, previously known only by 6 species in one genus. In Chapter Five I report the discovery of a new seed predator - Coleophora triplicis - on a previously undocumented host, the endangered Aster Symphyotrichum laurentianum from Prince Edward Island; the identification of the predator in this case was carried out by using DNA barcoding on its larvae, and comparing it to the comprehensive DNA barcode library for the north American Coleophora on the barcode of Life Data Systems (BOLD). |
