Lepidoptera collected in the Canadian Arctic during the Tundra Northwest 99 expedition

During the Swedish-Canadian icebreaker-based expedition to the Nearctic in summer 1999 (July and early August), moths and butterflies (Lepidoptera) we re collected during short, helicopter-aided visits to eight sites in the Ca nadian archipelago, three sites on the Canadian mainland near the arctic co ast and also at Thule Air Force Base in north Greenland. Some of the visite d sites (notably those on Melville Peninsula, Somerset Island and King Will iam Island) have not previously been investigated with respect to their ins ect faunas. Several records thus represent species range extensions. They g enerally corroborate an earlier hypothesis, based on a floristic zonation s cheme, which has been used as a framework for understanding the distributio n of Arctic butterflies.