Why are there so few aphid species in the temperate areas of the southern hemisphere

Abstract

An answer to this question is proposed on the basis of the assumed evolutionary history of aphids based on palaeontological studies, zoogeographical data and estimated origin of each aphid genus in the world. An adaptive radiation of Aphididae and Lachnidae occurred rather late in the Tertiary on the northern hemisphere, and the tropics acted as a barrier. Most aphid genera endemic to the temperate regions of the southern hemisphere belong to other groups. The life cycles of aphids are discussed, and it is concluded, that the life cycles characteristic to most aphids in the temperate regions of the northern hemisphere are developed as an adaptation to the climatic conditions there.