PEST

NAME
Diamond Beetle, Diamond Weevil
Chrysolopus spectabilis

ORDER
Coleoptera

FAMILY
Circulionidae

Description of the Pest
The adult weevil is black with blue green patches dotted on its back and is up to 25mm long. The white fleshy larva is legless up to 20mm long and both adult and larva have chewing mouth parts.

     

Appearance and Distribution of the Pest
There is a loss of colour in the foliage and stems die back. It is widely distributed throughout eastern Australia.

Period of Activity
These insects have a Holometabolouslife cycle, ie. When metamorphosisis observed during the pupalstage.
The alarvae is active during summer followed by the adult.

Damage Caused
The adult chew on the leaves of the host plant and cause little damage and the larvae forms tunnels in the base of the tree or in to the roots.



Susceptible Plants
Stressed or older plants are more susceptible to attack and the normal host plants are Wattles (Acacia species).

Cultural Control
Stressed trees can have there culture improved, but once the symptoms are seen, such as the death of the main trunk replacement of the plant is the main course of action.

BiologicalControl
There is no effective natural control.

Chemical Control
It is not possible to control with tree injection as the larvae bore into the woody parts of the plant