These collected works reflect different levels of taxonomic work on mosquitoes (Diptera: Culicidae) in the Americas, with emphasis on species in the subfamily Culicinae. In Chapter 2, I provide a comprehensive review of the literature that led to the need for a taxonomic revision of the subgenus Ochlerotatus Lynch Arribálzaga, 1891, followed by the revision itself. This work is a major taxonomical reappraisal of the group and provides a definition for the subgenus, a critical step towards stabilizing the genus Ochlerotatus Lynch Arribálzaga. In total, two species are elevated out of synonymy, and two synonymized names are moved to the list of synonyms of another taxon. One new species is described, Ochlerotatus (Ochlerotatus) brisolai sp. nov., and nine species are redescribed. In Chapter 3 we review of the fauna of Culicidae of Wisconsin, USA, based on both a comprehensive review of the literature and identification of museum specimens. These data are compiled in an annotated checklist with figures, tabular data and maps to show the distribution and composition of the fauna of the state. The work presented in Chapter 3 inspired a survey of the mosquito fauna of the UW-Madison Arboretum, described in Chapter 4. This work contains information on the species composition, seasonality and habitat distribution of the Culicidae in a natural area in Madison, WI, USA. That work also provided material that led to Chapter 5, which is a description of a new species of the Stimulans Group of mosquitoes, Ochlerotatus mirabilis sp. nov. Finally, the works performed in the Arboretum were one of many inspirations for a reappraisal of characters used to distinguish two species of Culex that are common to this area and play important roles in the transmission of West Nile Virus (Chapter 6). This body of research highlights the importance of correctly identifying a specimen according to its designated classification, as a fundamental step in research in the biological sciences.