In Australia, in the five Butterfly families, there are about 400 species of Butterflies.
In Australia, in the other LEPIDOPTERA families, there are estimated to be about 20,000 species of Moths.

The species in the Butterfly families have some general features in common which distinguish them from species in the Moth families:

Most of the Caterpillars which we have found are the larvae of moths. Moths far outnumber butterflies both in numbers and species. In Australia, there are over 10,000 named species of moths compared with only about 400 species of butterflies. Added to this, in Australia, it is estimated that another 10,000 species moths have yet to be studied and named, whereas very few butterfly species remain to be discovered.

The common names of many moths are derived from the behaviour and appearance of their caterpillars. This situation is unlike that for butterflies, for which the common names are usually derived from the adult forms. The difference stems from the fact that common names are given by ordinary people and are handed down by generations. Butterflies fly mainly by day, so ordinary people mainly see the adults, whereas moth adults fly mainly at night. But moth caterpillars are often made conspicuous by the damage they do to plants, as the caterpillars of many moth species are important agricultural pests. Thus the stage of moth development that is most often encountered by ordinary people by day is the caterpillar.

Very few Australian moths have English common names, as there have been only 200 years or so of English settlement in Australia. Even the moth families are usually referred to in Australia by derivatives of their scientific names. The situation is very different from that in Europe and America where most common moth species have common names. In these pages, we give many of the European and American names out of deference to overseas visitors to our pages.