Systematics and Comparative Biology of Aquatic Insects

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Freshwater covers less than 1% of the Earth’s surface yet harbors 10% of all known animal species — the majority (60%) of which are aquatic insects. The roughly 100,000 species of aquatic insects likely represent half the actual number, and it is likely they constitute closer to 80% of aquatic animal diversity. Insects play a vital role in aquatic food webs as primary consumers, detritivores and predators. They sustain both vertebrate and invertebrate predators and serve as barometers of environmental quality. As freshwater habitats are widely recognized as among the most threatened on Earth, it is important to gain a better understanding of aquatic insect biodiversity and the role they play in ecosystem function. True flies (order Diptera) are by far the largest contributor to freshwater biodiversity, constituting more than half of all aquatic insects. Among these are the bloodsucking flies (e.g., mosquitoes, black flies, tabanids and biting midges), which include among the most serious vectors of disease to humans and other animals. As taxonomy is the foundation of all scientific disciplines dealing with organisms, it is especially important to document these medically important insects. The Royal Ontario Museum — with its world-class collections of dragonflies and damselflies (Odonata), caddisflies (Trichoptera) and black flies (Diptera: Simuliidae) — provide an outstanding venue for taxonomic and ecological studies of these important groups of aquatic insects. Systematics unifies all areas of biology by establishing a conceptual framework for interpreting the properties and activities of organisms. Classifications developed by systematists integrate comparative information about species across many disciplines, ranging from molecular biology and ecology to resource management and health sciences. Although activities such as taxonomy, phylogenetic analysis and classification continue to be at the core of my program, a primary objective my research is to provide a sounder basis from which to interpret evolutionary, ecological and behavioral phenomena. The proposed research focuses particularly on my on-going investigations into the systematics and evolution of black flies (Diptera: Simuliidae) — a group of considerable medical and veterinary importance. Project 1 will clarify the taxonomy and relationships of primitive lineages of Australian black flies, providing a sounder basis from which to construct a natural classification of the family. Project 2 aims to use new analytical tools to quantify shape variation in morphological structures of black flies. I anticipate that phylogenetic signal will be detected in a number of long-neglected character systems, providing a hitherto untapped source of information for evolutionary studies. This approach will be especially beneficial for the study of fossils, in which morphological characters are often obscured or otherwise impossible to evaluate. Black flies are arguably the most completely know group of insects in North America in terms of their taxonomy; however, basic ecological information is lacking for many species — especially in northern Canada. With growing concern about the effects of global climate change it is increasingly important to address knowledge gaps in this medically important group of insects. In order to address this deficiency, I propose two ecologically oriented projects in the Canadian arctic. Project 3 aims to gain a better understanding of what limits the distribution of bloodsucking species, allowing predictions to be made about the rate of northern migration. These data have important implications for wildlife management. Project 4 goes a step farther by assessing host preferences and vector potential among northern species of bloodsucking black flies.