Lepidoptera are among the most successful groups of insects. They are found on all continents, except Antarctica. Lepidoptera inhabit all terrestrial habitats ranging from desert to rainforest, from lowland grasslands to montane plateaus but almost always associated with higher plants, especially angiosperms (flowering plants). Among the most northern dwelling species of butterflies and moths is the Arctic Apollo (Parnassius arcticus), which is found in the Arctic Circle in northeastern Yakutia, at an altitude of 1500 meters above sea level. In the Himalayas, various Apollo species such as Parnassius epaphus, besides others, have been recorded to occur up to an altitude of 6,000 meters above sea level.: