A Molecular and Morphological Investigation of the Springtail Genus <i>Orchesella</i> (Collembola: Entomobryomorpha: Entomobryidae)

Chapter 1 is devoted to a molecular overview of the North American members of the springtail genus Orchesella using mitochondrial and nuclear DNA. Both genes strongly support the presence of four major clades within Orchesella. Chapter 2 is a morphological revision of the species near Orchesella celsa Christiansen & Bellinger. Five new species are described based largely on chaetotaxonomical differences in. Chapter 3 is an investigation into the origins of United States populations of two introduced European members of the genus, Orchesella cincta Linnaeus and Orchesella villosa Linnaeus. Mitochondrial data between populations from the two continents indicates multiple introductions for O. cincta, and the possibility of cryptic species in the European populations of O. villosa.