A COMPARATIVE APPROACH TO THE ENTOMOLOGICAL DIVERSITY OF POLAR-REGIONS

The Arctic and Antarctic are both cold deserts but show contrasting ge ographic and climatic features. Marked differences are notice able in the richness of insect communities at these high latitudes. In the nor th, a continuous terrestrial gradient links sub-Arctic and Arctic regi ons, while in the south, the Southern Ocean is an efficient barrier be tween the sub-Antarctic and the Antarctic. In spite of stressful envir onmental conditions, insects are present but species richness is poor. Functional diversity is subordinate to these constrained features. Ho wever, ecological and physiological adaptations are varied and general ly show no taxonomic pattern. On sub-Antarctic islands, the recent inc rease in human activities has precipitated a dramatic increase in ento mological diversity. In the Arctic, the spectacular underrepresentatio n of the Exopterygota cannot be explained only by biogeographic criter ia. An ecophysiological interpretation is suggested and leads to an ev olutionary hypothesis of entomoiogical biodiversity in polar regions. (C) Elsevier, Paris.