PEST
 
   NAME
     Tip Borer
     Various Tip Borer Species
 
   ORDER
     Various

Description of the Pest
There is many species of moths which are brown, blackish or white up to 30mm long. Generally the fleshy, greenish to cream coloured larvae grow to 25mm long and are sparsely hairy. The Callistemon Tip Borer is laid by a metallic to blackish moth and the larvae are creamy grubs that have true legs. Some larvae are very active when disturbed such as the fleshy Macadamia Twig Girdler which has darker strips on its body and a dark head.

  Dieback Borer Damage

Dieback Borer (Platyomopsis armatula) adult is a grey-brown beetle up to 20mm long with small lumps on its wing covers and long antennae. The 15mm long cream coloured larva tunnel under the bark and feed on the sapwood causing ringbarking. The entrance to the tunnel is covered in frass and plants in the Myrtaceae family such as Eucalyptus species are susceptible.  
 
Elm Twig Girdler (Oberea tripunctata). The adult beetle feeds on twigs causing girdling then deposits eggs during spring. The lava tunnels down the centre of the stem from the girdled point and overwinters in the tunnels. Twigs up to 14mm diameter may snap off at the damaged point and Ulmus species are normally the host.

Mahogany Shoot Borer (Hypsipyla grandella). The adult is a greyish-brown moth with a wingspan up to 45mm with the wings and veins distinctly overlayed in black. It deposits oval eggs that are tiny 0.50mm wide normally deposited in the leaf axil and change colour from white to red in the first 12 hours. In 3 to5 days the larvae emerges and can grow to 25mm long and is brownish white when young and maturing to bluish with a brown head capsule. Swietenia species are damaged as the larvae bore into the new shoots normally during spring or during the rainy season. The shoots and branches wilt then collapse. This is a major economic pest for cultivated trees.

Red Cedar Tip Moth (Hypsipyla robusta) adult is a grey moth with a wing span up to 20mm across and produces fleshy lava with true legs up to 20 mm long that tunnels into the tips of twigs. The tunnels are surrounded by webbing that is littered with pelleted droppings and is normally found on Toona species.

Staghorn Borer larvae grow to 15mm long and are greyish with true legs and the grey adult moth has a wingspan up to 20mm across. It attacks Platycerium species by eating tunnels into the sterile fronds.

Appearance and Distribution of the Pest
They are found mainly on the coast but also inland and are distributed by flying with the assistance of wind.

Life Cycle
These insects have a Holometabolous life cycle, ie. When metamorphosis is observed during the pupal stage.
Eggs are laid in bark on the growing tips. Larvae shelter in tunnels they create in the wood, up to 20mm deep.

Period of Activity
Active throughout the year in warm climates and are commonly found from tropical to sub-tropical and temperate regions.

Damage Caused
Generally the symptoms of tip borers is yellowing and curling of the leaves which wilt then die or shoots become blackened and are noticeable in the tree. Extensive feeding by a number of larvae causes dieback but normally, this is a minor pest.
The larvae emerge from their tunnels at night, to feed on the bark around the entrance holes. Entrance holes are covered by a layer of chewed wood fragments (“frass”) and silk webbing. Most damage appears on twigs and new growth.

 Typical larvae

The Callistemon Tip Borer tunnels down the centre of the twigs causing then to die or break off and the Macadamia Twig Girdler (Neodrepta luteotactella) form tunnels in sapwood that are covered in fine webbing that is dotted in brown excreted pellets. This is the same appearance as the Banksia Web-covering Borer (Xylorycta strigata) larva makes, as it tunnels down the centre of shoots.

Susceptible Plants
Many native and ornamental plants are susceptible to tip borers such as Callistemon, Melaleuca, Banksia, Hakea, Macadamia and Stenocarpus species

Eucalyptus, Callistemon, Corymbia, Leptospermum and Melaleuca species are attacked by the Dieback Borer (Platyomopsis armatula). Twigs and small branches are attacked and the larvae causes ring bark. Affected branches break easily in high winds.

Sambucus, Yucca and Delphinium species are attacked the Common Stalk Borer (Papaipema nebris) which attacks the stems causing the plant to wilt and topple over. 

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, or tunnels plugged.  Infested perennials or annuals should be removed and destroyed.

Biological Control
No effective biological control.

Chemical Control
Spray with Carbaryl (including the trunks or stems) if necessary while the insects are active.
Note
Always read the label for registration details and direction of use prior to application of any chemicals.