Australasian distributions in Trichoptera (Insecta) - frequent pattemorarare case?

Australasian distributions are defined as intercontinental ranges with areas in Asia and Australia. The aquatic insect order Trichoptera is reviewed within the context of obtaining figures on the abundance of Australasian distributions at different taxonomic levels. Continuous and disjunct patterns are distinguished. Asia and Australia have 17 families in common. Ten families are widespread and regarded as uninformative. Seven families exhibit Australasian distribution patterns, which are depicted on a global scale and discussed in some detail as to age and origin. Australasian distributions carry a different weight at different taxonomic levels: they make up 60 % in families, about 20 % in genera and 1% or less in species. It is concluded, that only a minor part of the Asian and Australian groups are involved in the Austral-Asian interchange.