Cabbage White Butterfly
- Colour: The caterpillar (larva) is initially pale yellow with fine hairs, before turning green. It has narrow yellow lines on its body which are sometimes hard to see. The upper side of the butterfly (adult) is white with a black tip on its forewing (front wing) and a black patch on the front edge of its hindwing (back wing). A male has one black spot on its forewing, while a female has two black spots. Looking from underneath, the forewing is white with two black spots and the hindwing is yellow.
- Size: the caterpillar is about 3.5 cm; the butterfly is up to 5 cm (wingspan).
- Diet: caterpillars eat mainly the leaves of cultivated and introduced plants in the family Brassicaceae (such as cabbage and cauliflower), and can be a major pest of these crops. Adults feed on nectar from a variety of plants.
- Before it starts to eat, a caterpillar lays down silk to which it attaches itself for support.
- Movement: when resting, a caterpillar aligns itself with the leaves of the host plant so that the yellow lines on its body look like the veins of the leaf, but if strongly handled or attacked, it ejects a fluid which can act as a repellent.
- Flight: adults start flying from early spring.
- Breeding: the females lay single eggs on the underside of host leaves. The eggs hatch into caterpillars after about four days and the caterpillars then eat for 17 days, before becoming pupae for eight days. They finally emerge as white butterflies. There may be several generations each year.
What to Observe
- Presence (to establish the first and last sighting for the season)
- Egg laying
- Chrysalis (butterfly emerging from its shell)
ClimateWatch Science Advisor
We expect butterflies to appear earlier in the year as a result of climate change warming the Earth. They may also start appearing in new areas as warmer temperatures enable them to live in environments that were once uninhabitable.
When To Look
- From early spring (September)
- Butterflies fly for more of the year in warmer areas
Where To Look
- All over Australia, but more widespread in the south.
- Widespread in urban areas, forests and woodlands. It is common wherever vegetable plants are found, so generally occurs around human habitation.
- Look on the leaves of vegetable plants for caterpillars, and around flowers for butterflies. They are common in urban gardens.
Another white butterfly: won’t have the two or three black spots on the upper side of the forewing. Also, the underside of its hindwing won’t be yellow.
Did You Know?
The Cabbage White Butterfly is an introduced species from Europe and was first recorded in Australia (Melbourne) in 1929. It has since become a pest, feeding on cabbages and other vegetables.
Two species of wasp introduced to control it have helped reduce the number and impact of the butterfly.