Appias paulina ega (Boisduval)
This is another migrant butterfly that occasionally ventures south from the hot tropics into temperate areas.
The species has angulate forewings, although they are the weakest developed for the five Appias species to be found in Australia. The sexes are strongly dimorphic, with the male being mostly white but with conspicuous yellow hindwings on the underside, while the female has broad dark brown to black margins to the wings. The male is very similar to the common Cabbage White (Pieris rapae). The former is distinguished by its more rapid flight (that is usually higher off the ground), the more intense yellow colour of the hindwing underside, the apex of the forewing is more angulate, and the forewing black spots are positioned more apically.
Photography © Museum Victoria Australia
Drypetes species (Euphorbiaceae) and Capparis species (Capparaceae). It prefers the tropical and subtropical species of these plants that grow in rainforest areas. None of the preferred hostplants occur naturally in South Australia. The larvae eat the softer green parts of the hostplant.
The butterfly is seen all year round in the tropical north of Australia. Many of these butterflies migrate south from Queensland during the southern warmer months, and those reaching the southern temperate areas of Victoria usually do so during January.
Normally a tropical butterfly. It is a strong migrant moving south into subtropical areas during the warmer months, usually along the humid east coast region of mainland Australia. Very few reach the southern coastal areas of Victoria, and there is a single record for Tasmania. Only in exceptionally humid years are they seen in the arid interior areas of Australia. It is unable to establish itself in the southern settled areas even if its hostplants are present as botanical specimens. Within South Australia the butterfly has only been recorded from Waikerie in the Riverland, where some males were identified during the humid year of 1974 . The most likely place where the butterfly will be seen in the future in South Australia is along the Riverland or along the Cooper Creek system in the Far Northeast Region. Other subspecies occur in the tropical Orient and Pacific islands.
Its hostplants normally grow in tropical and subtropical rainforests and vine thickets, and it is here that the butterfly is normally encountered. When in a migratory mode it can also be seen in high-rainfall open woodland areas.
A migrant. Common in the north of Australia.
No major threats.