Snowshoe hare (SSH) virus of the California encephalitis group of arboviruses was isolated from a pool of 60 female Aedes communis collected in the forested region of west-central Manitoba during the summer of 1976. This is the first reported isolation of SSH virus from Manitoba Aedes accounted for 99% of the 7,491 mosquitoes examined for arboviruses by suckling mouse inoculation. Seroconversion in 58% of 19 sentinel rabbits deployed in various vegetation types within the forested area is consistent with the hypothesis of widespread vernal cycling of SSH virus between univoltine Aedes and mammals in the boreal forest of Canada.
