Description
Cabbage tree moths have a wingspan of about 40 millimetres. They are pale brown and camouflage themselves by carefully aligning with the veins on dead cabbage tree leaves. They can also be found hiding amongst dead foliage hanging from established cabbage trees. Adult moths play a role in pollinating cabbage tree flowers.
Caterpillars are green and are well concealed against live cabbage tree foliage. When they are fully grown, they are about 25 millimetres long. Young caterpillars feed on unopened cabbage tree leaves and their damage may not be visible until the leaf unfurls.
Small caterpillars chew grooves along the leaf surface causing leaf scarring while larger caterpillars chew holes and notches in leaves.
Common native plant hosts
| Scientific names | Māori/common names |
|---|---|
| Cordyline spp. | Tī kōuka, cabbage tree, tī |
Scientific names
Cordyline spp.
Māori/common names
Tī kōuka, cabbage tree, tī
Symptoms and damage
Cabbage tree moths are nocturnal. Feeding activity creates holes and notches in cabbage tree leaves. Caterpillars feed on young unopened leaves of cabbage trees but plants can tolerate significant leaf loss. Damage is mainly aesthetic.
Prevention and control tips
- Cabbage tree moths don’t usually require control, but treatment may be needed in the case of heavy infestation in small young plants.
- Caterpillars live and feed between young leaves which makes them difficult to target using contact insecticides. Apply insecticides in the evening when caterpillars are more likely to leave protection to feed.
- Bacillus thuringiensis.
Natural predators
The following are known to feed on cabbage tree moth caterpillars:
- birds.
- brown soldier bugs.
- hoverflies.
- parasitoid flies.
- parasitoid wasps.