Torrenticola trimaculata n. sp. (Parasitengona: Torrenticolidae), a three-spotted water mite from eastern North America: taxonomic history, species delimitation, and survey of external morphology

Torrenticola trimaculata Fisher n. sp. is described from eastern North America as the first in a series of descriptions on Torrenticolidae. As such, the study includes expanded discussions of methods, early taxonomic history, and numerous images surveying external morphology using a diversity of imaging methods. Species hypotheses were supported with analysis of the "barcoding" region of COI. Torrenticola trimaculata is found to be a wide-ranging, variable species with two distinct morphs that do not coexist locally. Also, we report the first record of the diatom, Cocconeis placentula Ehrenberg 1838, as epiphytic on water mites.