Belenois java (formerly Anaphaeis)
Family Pieridae
Order Lepidoptera
The Caper White Butterfly is a distinctive black and white butterfly that belongs to the Family Pieridae and may be seen during its spring migration in eastern Australia.
Caper White Butterflies are medium-sized white butterflies with black margins to their upper wings and yellow, black and white underwings.
Their caterpillars eat plants belonging to the caper family (Capparis spp) that grow in the northern parts of inland New South Wales and in Queensland. These include native capers and warrior bushes.
In spring many Caper White Butterflies migrate to where caper shrubs and creepers are more common. They usually fly inland, west of the Great Dividing Range, but a westerly wind may blow them off course and they may then be seen by people living along the coast. They maintain a rapid flight about 2 m - 3 m above the ground during the day, resting on shrubs and trees at night.
Migrations in New South Wales have been observed moving in a southerly direction during November and December. However, in the Australia Capital Territory, north-easterly flights have been observed, and both northerly and southerly flights have be reported near Sydney.
Numbers in migrations can be very large. In some cases, the adult butterflies can clog car radiators, causing overheating.
An interesting feature of this species is that it regularly migrates to areas where there are no food plants for its caterpillars. It is not understood why this behaviour has evolved.
Another feature of this species is that the caterpillars often occur in such large numbers on the food plants that they completely strip them of edible leaves. However the native capers and warrior bushes normally recover from this seemingly destructive behaviour.
Copyright © Australian Museum, 2003
This page: http://www.amonline.net.au/factsheets/caper.htm
