PEST

NAME
Cossid Wood Moths
Various Wood Moth Species

ORDER
Lepidoptera

FAMILY
Coccidae


Description of the Pest
This insect has a complete metamorphosis: egg - larva - papa - adult. Eggs are laid on a damaged or soft part of the plant. The larvae are creamy pink caterpillars; they have chewing mouth-parts. Larvae tunnel into the sapwood, for years in some cases; they pupate inside the tunnels. Tunnels are round and packed with sawdust-like excreta (frass). The adults are moths with grey and brown patterned wings, up to 250mm across.
These insects have a Holometabolouslife cycle, ie. When metamorphosisis observed during the pupalstage.


Appearance of the Pest
Tunnels are very symmetrical, appearing as holes caused by an auger, or drilled into the wood. Active tunnels will often have frass visible at the entrance; some species feed on the bark around the entrance.

Period of Activity
Eggs are laid in early spring; the larvae of some species may remain active for several years.

Susceptible Plants
Many species of Acacia, Eucalyptus, Banksiaand Leptospermumare susceptible.

Damage Caused
The tunnels of the cossid wood moth larvae may ring-bark the tree. Damage may not be apparent until die-back occurs, or the branch falls.
In forestry the larvae typically attack young trees with trunks up to 200mm diameter. A secondary damage results from Black Cockatoos foraging for the larvae, damaging the trunk and sometimes felling the tree.

Control
Remove damaged bark and timber. Larvae may be destroyed or removed by inserting and twisting a length of stiff wire into their tunnels. Improve the quality of the plant by maintaining appropriate feeding and watering, and removing or repairing damaged limbs.