Insects and Related Terrestrial Invertebrates of Ellef Ringnes Island

Résumé

Reports results of collecting and observing arthropod fauna over a 25-day period in July-Aug. 1960 at the Polar Continental Shelf Project base at Isachsen, where the summers are unusually cold. Some 75 species are believed present in an environment closely approaching the limits of biotic tolerance, and detailed descriptions are given of most of these (Latin names), with their characteristic habitats and global distributions. They include spiders, mites, springtails and insects, particularly midges. The view is elaborated that only those species able to withstand frequent interruptions of development in various stages and a life cycle extending over several years are able to survive. Specimens at all stages of development were found simultaneously. Other adaptations to extremely severe environmental conditions were mentioned. The role occupied by the lemming Dicrostonyx groenlandicus is described, as the habits of a third of the arthropod species are linked with it. The very low flying habits of some species are noted. The age of the entire island biota is placed within the last 200 years, and the source area considered to be the islands to the east, principally Axel Heiberg, the means of dispersal being wind, ice rafts, mammals and birds.