Term of Award

Spring 2014

Degree Name

Master of Science in Biology (M.S.)

Document Type and Release Option

Thesis (open access)

Department

Department of Biology

Committee Chair

Quentin Fang

Committee Member 1

Dmitry Apanaskevich

Committee Member 2

Lance Durden

Abstract

Dermacentor is a recently evolved genus of hard ticks (Family Ixodiae) that includes 36 known species worldwide. Despite the importance of Dermacentor species as vectors of human and animal disease, the systematics of the genus remain largely unresolved. This study focuses on phylogenetic relationships of the eight North American Nearctic Dermacentor species: D. albipictus, D. variabilis, D. occidentalis, D. halli, D. parumapertus, D. hunteri, and D. andersoni, and the recently re-established species D. kamshadalus, as well as two of the Neotropical Dermacentor species D. nitens and D. dissimilis (both formerly Anocentor). We sequenced portions of the mitochondrial cytochrome oxidase subunit I (COI) gene, and the ribosomal 12S and 16S genes from the largest sampling of North American Dermacentor ticks analyzed to date. In all analyses, we found that North American Dermacentor ticks form a monophyletic lineage, and that all four species of one-host Dermacentor ticks also form a monophyletic lineage within the genus. The placement of the former Anocentor species, D. nitens and D. dissimilis in Dermacentor is also well supported. The winter tick, Dermacentor albipictus, has a complex structure in all analyses that warrants further study into the possibility of a species complex. Dermacentor kamshadalus, formerly a synonym of D. albipictus, shows the same complex structure under analysis of these three mitochondrial genes, and should also be further molecularly examined.

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