Seasonal abundance and composition of mosquitoes in boreal forest caribou habitats of Northern Alberta

Arthropod borne Bunya- Flavi- and Alphaviruses have been present in Albertan mosquito populations for several decades, the most recent event being the appearance of West Nile virus in 2003. Culex tarsalis has been identified as the main vector for West Nile Virus transmission in Western Canada, however, other arthropod species are also proposed as potential vectors. The variation in Albertan ecosystems displays a notable division at approximately 53° latitude between habitats favorable for Culex spp mosquitoes in the south and Aedes / Ochlerotatus spp in the north. The boreal forest ecosystem north of 53° provides a large number of semipermanent standing water bodies which can facilitate the breeding of very large mosquito populations. In the present study, biweekly sampling of mosquito populations during the summer season (June-September) is conducted to determine abundance and species composition in five major boreal forest regions. These regions are important habitats for endangered woodland caribou in Northern Alberta. Mosquito species abundance and composition will be evaluated and the results compared with previous data from the collection of samples from tudra sites along a migratory barren-ground caribou herd in the Northwest Territories between 2007 and 2009. Examination of the collected data, alongside climate and topographical information, will provide important information for risk assessment of arboviral disease risks to boreal ungulates. The study may also provide evidence for a possible shift of mosquito species composition and seasonality in this sensitive ecosystem.