Analyse quantitative des populations larvaires de moustiques (Diptera: Culicidae) dans l'Hémiarctique (Poste-de-la-Baleine, Québec)

Abstract

The Great Whale River area (55°16′ N; 77°48′ W) is located at the fringe between the boreal forest and the forest tundra of the "hemiarctic" zone (between 55°N and the absolute limit of trees, as defined by J. Rousseau (1952. Can. J. Bot. 30: 436–474)). Two types of habitats are particularly productive for mosquito larval populations: arctic–alpine rock pools and bogs with palsas. Six of the 17 species present across the area have a high larval frequency of occurrence: Aedes hexodontus (60%), A. punctor (28.4%), A. excrucians (26.3%), A. communis (25.8%), A. pullatus (21.6%), and A. pionips (14.7%). Aedes impiger constitutes 36.2% of the captured imagos, A. hexodontus 31.8%, A. pullatus 10.8%, Culiseta alaskaensis 5%, and A. nigripes 3.8%. A quantitative analysis of the ecological distribution of the mosquito larvae is presented, illustrated, and discussed. Three clusters are distinguished: an A. communis – A. pionips group, an A. hexodontus – A. punctor group, and a third, less correlated group with A. pullatus and A. excrucians, characteristic of the alpine rock pools. Results from a principal components analysis indicated that in the area mosquito species are relatively ubiquitous and seem more related to the types of pools than to the general habitats comprising these pools.