THE EFFECTS OF AMPHIBIAN PRESENCE AND PREDATION ON MOSQUITOES C

Due to their importance as vectors of human diseases such as West Nile, dengue, and malaria, extensive scientific research has been done to examine the factors regulating mosquito populations. Mosquito larvae are aquatic and often share habitat with other species, including amphibians. However, it is not well known whether amphibians regulate mosquito populations. Amphibian populations are declining globally due to many factors, including habitat destruction, infectious diseases, and climate change. If amphibians influence mosquito population growth, for example, by reducing the rate at which mosquitoes lay their eggs or through direct predation of mosquito larvae, then the decline of amphibians worldwide could increase mosquito populations. We conducted a series of experiments to examine whether amphibian presence and predation of mosquitoes has a significant effect on mosquito populations. Specifically, I investigated whether the presence of Salamander tadpole species, Ambystoma maculatum, frog tadpole species, Lithobates clamitans, affected the rate at which mosquitoes lay their eggs, mosquito oviposition. I also examined whether amphibians prey upon mosquito larvae at different rates and whether the sizes of the amphibians affect consumption rate. Ambystoma maculatum consumed mosquito larvae at a much higher rate than Lithobates clamitans. Based on the number of mosquito eggs laid in containers with salamanders, salamander larvae do not contribute to lowering mosquito population densities in areas where mosquito habitats are predominated by vernal pools. Frog tadpoles also consumed mosquito larvae, although at a much lower rate. Though predation rates were very different between salamander and frog larvae, both frog tadpoles and salamander larvae could have significant effects on the survivorship of mosquito larvae, and thus may play an important role in regulating mosquito population density in vernal pools.