Aquatic Community Interaction Diversity and Mosquito Larvae

Mosquitoes comprise a diverse group of small flies (Diptera) in the family Culicidae which includes an estimated 3,600 described species. Colloquially we know mosquitoes as biting insects that pose a threat to humans and domestic animals as important vectors of disease. Although a minority of the described species of mosquitoes are not known as competent disease vectors, many competent vector species are highly common surrounding human habitations. Despite being important flying insects, mosquitoes undergo an entirely aquatic life cycle as developing larvae and pupae. During these developmental stages immature mosquitoes are most vulnerable to predation and competition for resources. Their habitats are highly variable in many factors including size, invertebrate diversity, and spatial heterogeneity. My dissertation research focuses on the larval stages of mosquitoes. The main questions of my research include: 1. What are the important interactions of co-inhabiting invertebrates including predators and competitors, with mosquito larvae? 2. Does environmental heterogeneity in the form of plant complexity influence the structure of invertebrate diversity in aquatic communities? 3. Does interaction diversity affect the abundance of mosquito larvae? My research includes four complimentary approaches to answering these questions. First, I conducted a meta-analysis on the use of natural enemies to control mosquito populations. Second, I developed simulation models to test the effects of plant, herbivore, and enemy diversity, abundance and diet breadths on sampling interaction diversity in artificial communities. Third, I conducted two identical mesocosm experiments with experimental manipulations of plant diversity and structural complexity in order to test the effects of those on aquatic invertebrate diversity andii mosquito abundance. Finally, I measured plant diversity and environmental heterogeneity in unmanipulated aquatic field environments to test the effects of plant diversity and environmental heterogeneity on invertebrate diversity and mosquito abundance. The results from my research show several important relationships between environmental heterogeneity, invertebrate diversity, interaction diversity, and mosquito abundance. 1. Natural enemy groups including predators, competitors, parasites, and pathogens can have important negative effects on mosquitoes. 2. Increased predator and competitor diversities reduce larval mosquito abundance through direct and indirect effects. 3. Plant diversity and environmental heterogeneity have positive effects on community invertebrate diversity. 5. Greater interaction diversity in aquatic systems reduces larval mosquito abundance. These results show the importance of protecting and encouraging biodiversity as components of effective larval mosquito control programs. Careful management of aquatic macroyphyte diversity and environmental heterogeneity will help reduce larval mosquito abundance