deformed leaves on our corymbia tree

[Carolyn6285]

Help please-can anyone advise what is happening with our tree? It is 6 months old, receiving full sun. 

 

[EricL · Accepted solution]

Hello @Carolyn6285 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about your Corymbia tree.

From the photo and your description, this looks very consistent with psyllid damage, commonly called lerp infestation, which is quite common on young Corymbia and eucalyptus trees. The white, crusty or cottony material on the leaves is not a fungus, but a protective covering made by sap-sucking insects. These insects feed on the leaf tissue, which causes the leaves to curl, tear, skeletonise or drop prematurely, exactly as you are seeing. Young trees are particularly vulnerable in their first year while they are still establishing.

Full sun is not the issue here, as Corymbia actually prefers it, but stress from planting, limited root development, or inconsistent watering can make the tree more attractive to psyllids. Six months after planting is a very typical time for this problem to appear. In most cases, healthy trees will eventually grow out of it once their root systems are established and natural predators move in.

What you can do now is focus on tree health rather than aggressive chemical control. Make sure the tree is being deeply watered rather than lightly and frequently, especially in hot or dry weather. A thick layer of mulch around the base, kept clear of the trunk, will help regulate soil moisture and reduce stress. If the infestation is heavy, you can hose the leaves with a strong jet of water to physically knock the insects off, or use a low-toxicity option like horticultural oil such as Seasol 1L EarthCare White Oil Insect Spray or OCP 750ml Ready To Use Eco-Oil, applied in the early morning and only if needed. Avoid systemic insecticides, as they can harm beneficial insects and often make the problem worse long-term.

If new growth starts to appear clean and healthy over the next few months, that is a good sign the tree is coping and recovering.

If you need further assistance, please let us know.

Eric

[mich1972]

@Carolyn6285 The top leaf in the photo looks curled up and may possibly have a tiny grub cocooned inside it. I would uncurl it to see if it does. 🙂🌿

[Carolyn6285]

Thanks so much for the detailed information. Very helpful.