Ants of the Yukon Ants (Hymenoptera: Formicidae)

Abstract. Ant material examined from the Yukon suggests that 19 recognized species occur there, taking into account outdated species taxonomy for the genera Myrmica, Leptothorax (sensu stricto) and Formica that compose the core of the ant fauna of the Yukon. The Palaearctic Formica gagatoides, a species associated with taiga environments in Eurasia, is recorded for the first time in North America. The species assemblage is characteristic of the boreal coniferous biome with elements restricted to southern or northern areas. Northern elements are Leptothorax acervorum and Formica gagatoides, which appear to be candidates for Beringian survival of their Nearctic populations. The ants Formica neorufibarbis and F. subnuda may well also have northern populations that have afterwards intermingled with those coming from the south. No species are expected to be limited to the Yukon; most of them have already been reported from adjacent territories. Most species exhibit a transcontinental range and latitudinal extensions southwards along the Cordilleran system. The most common species like Myrmica alaskensis, Camponotus herculeanus and Formica neorufibarbis have been detected as fossil remains in Quaternary palaeoecological studies, indicating their long-standing presence in boreo-arctic habitats. Many woodpeckers (Piscidae) occurring throughout the forested Yukon include wood-nesting ants in their regular diet, indicating a general presence of ants. Résumé. Les fourmis (Hymenoptera: Formicidae) du Yukon. La myrmécofaune du Yukon comprend au moins 1