Les libellules (Odonata) des grandes rivières du sud du Québec

Abstract

ABSTRACT The dragonflies (Odonata) of the large rivers of southern Québec, Canada, such as the Ottawa River and its tributary, the Petite Nation River, have not been collected, observed and studied as thoroughly as the Odonata of inland lakes, ponds, marshes, and streams. The author gives an account of his collection and studies of the odonate fauna of these two rivers between 1988 and 1999. Specimens consist mainly of larvae and larval skins Given that many threatened species of odonates (especially of the family Gomphidae) are associated with flowing water, the importance of marshalling conservation efforts is stressed. From the 26 species of gomphids recorded for the province of Québec, 22 have been found in the Outaouais region and 14 have been collected in the Ottawa and Petite Nation Rivers. Furthermore, a number of these gomphid species, while abundant in nature, are rarely seen in the adult stage. While many countries have just about lost their riverine species, there is still time to salvage what is left of the odonate populations in the Ottawa and Petite Nation Rivers. Systematic collecting of exuviae (cast-off cuticle of larvae) and larvae will enable dragonfly workers to assess the state of populations of the different taxa and promote measures to protect them from extinction