Date of Graduation

5-2016

Document Type

Dissertation

Degree Name

Doctor of Philosophy in Entomology (PhD)

Degree Level

Graduate

Department

Entomology

Advisor

Ashley P. Dowling

Committee Member

Tim Kring

Second Committee Member

Don Steinkraus

Third Committee Member

Andy Alverson

Fourth Committee Member

Jeffrey Silberman

Keywords

Biological sciences;Acarology; Phylogenetics; Species description; Systematics; Taxonomy; Water mites

Abstract

Mites are notorious for being under-studied and incomplete knowledge of distribution, life-history, and morphology are commonplace. They typically gain attention through the relatively few pest species that plague our crops, pets, or bodies. Despite representing a successful radiation with an estimated 3–5 million species, relatively few mite lineages attract research attention from non-acarologists. However, the largest radiation of all mites—Parasitengona—has potential to bridge the gap between specialists and non-specialists. Parasitengona are the butterflies of the mite world. Obvious are the bright red mites searching for pollen on concrete, or the large, furry velvet mites coming out to mate after spring rains. The subject of this dissertation deals with the most successful of these mites—water mites (Hydrachnidiae)—which have invaded freshwater ecosystems and diversified into over 6,000 species. Water mite larvae parasitize aquatic insects and affect the size and structure of their host populations by reducing host fecundity and longevity. Adult water mites are underwater predators that are sensitive to environmental stresses and are powerful bioindicators of water quality. However, despite their importance and ubiquity, most species are unnamed and the habits of nearly all remain a mystery. In high-quality streams throughout North America, one lineage outnumbers other water mites in terms of abundance and local diversity—long-nosed torrent mites (Torrenticola Piersig, 1896). Only 24 species have been described from this region, but many more are suspected. This dissertation is a taxonomic study of Torrenticola diversity in North America north of Mexico. Integrative methods are used to delimit species, including molecular phylogenetics and morphometrics. Morphology is investigated with modern methods such as low-temperature scanning electron microscopy (LT-SEM) and a diversity of imaging methods are utilized to showcase color. Phylogenetic analyses of multiple genes are used to elucidate relationships among species. In total, the number of species in the region is raised to 63. Distributions are examined with phylogenetic tools, which allow for discussions on biogeography and dispersal. Species are organized into 14 groups that span four larger species complexes. A key is provided to all species in the US and Canada.

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