Diversity and Ecological Structure of Northern Biting Flies

Contemporary climate change disproportionately impacts northern environments. Understanding these impacts requires knowledge of the ecological structure (e.g. diversity, abundance and distribution) of resident species. Biting flies are among the best-known groups of insects in northern Canada and are excellent sentinels for environmental change. The goals of this thesis are to determine how climate and geographical history affect the ecological structure of black flies and mosquitoes. Assessment of large-scale macroecological patterns revealed contrasts between Arctic and southern assemblages, while highlighting the importance of geographic history in structuring assemblages. Finer-scale sampling and analysis were used to assess the impacts of contemporary climate change on species ranges. A critical threshold temperature for the presence of biting species of black flies was found that approximates minimum requirements for flight and blood-feeding. Finally, mitochondrial DNA markers allowed the assessment of cryptic diversity in a widely distributed assemblage of northern black flies of the genusM.Sc