Biogeography of New Guinea leafhoppers (Homoptera: Cicadelloidea)

Abstract

Australia is flanked by two large islands, Tasmania and New Guinea. The first named has a cool temperate climate and the latter lies in the tropics. Although these islands are separated from each other by a distance of some 3500 km and have completely different climates they resemble each other in both being the meeting place of the same three, independently evolved, faunas and floras, though the proportions in which these are represented in the two islands are very different. Tasmania has dominantly Australian biota, a strong “Antarctic” element and a few organisms, such as the swallow-tail butterfly Graphium macleayanus and some leafhoppers belonging to the genus Kolla, of presumed northern, Oriental origin. New Guinea, on the other hand, has a dominant Oriental invertebrate fauna and flora, a restricted Australian invertebrate element, a largely Australian vertebrate fauna, and very small Gondwanaland representation. Another feature common to both islands is the restriction of the southern faunas and floras to high altitudes though their alpine associates may be very different. For example, while forests in Tasmania dominated by the Southern Beech, Nothofagus, are gloomy places devoid of color, in New Guinea these trees support epiphytic orchids and rhododendrons with variously colored flowers.