PEST

NAME
Fruit Tree Borer
Maroga melanostigma

ORDER
Lepidoptera

FAMILY
Oecophoridae

Description of the Pest
Adults are white, satiny moths with 40-60mm wingspans; their black abdomens are fringed with orange-brown hair and tufted at the tip. Larvae are reddish brown with a few hairs, up to 50mm in length.

Appearance and Distribution of the Pest
An Australian native pest that is found on the coast or inland from temperate to subtropical regions.

Life Cycle
This insect has a Holometabolouslife cycle, ie. When metamorphosisis observed during the pupalstage.
Eggs are laid singly, in bark normally in the branch junctions. After the eggs hatch the larvae shelter in the shallow tunnels they create in the wood, up to 60mm deep. The tunnel entrance is closed with webbing and the lava pupates, emerging the following summer.



Period of Activity
The pest is active throughout the warmer months and the lava overwinters in its sealed tunnel.

Damage Caused
Larvae emerge from their tunnels at night, to feed on the callus tissue around the entrance holes. Entrance holes are covered by a layer of chewed wood fragments ("frass") and silk webbing. Most damage appears on the branches, especially at junctions. Extensive feeding may girdle the branch cause ring-barking.
On inspection, the wound is covered in webbing material and on removal the true extent of the damage is revealed, bear wood. These areas may be infected by wood rot fungi.

     

Susceptible Plants
There are many plants that are attacked by the Fruit Tree Borer including; Acacia, Banksia, Callicoma, Lagerstroemia, Eucalyptus and Jacaranda species, and flowering stonefruit.
Factors that contribute to attack are infertile poorly drained soils or damage to the bark, mechanically or from sunscald.

Cultural Control
Larvae may be destroyed after exposure by pulling away the covering pad of frass, or by pushing a length of wire into the tunnel. Damaged branches may be removed. Use correct tree surgery techniques to seal the wound.
Improve the vigour of the tree by lightly cultivating the surrounding soil then fertilise and water. It may also be lightly pruned to encourage new growth.

BiologicalControl
No effective biological control, but several parasites and predators keep the numbers down.

Chemical Control
Spray with Contact insecticides(including the trunks).
Note
Always read the label for registration details and direction of use prior to application of any chemicals.