How to treat scale infestation on Lilly Pilly?

[beexdee]

Hi everyone, can i get some help on an infestation problem.

I’m new to gardening and just recently moved into my first house. What I think is a 3m tall Lilly Pilly tree is infested with what I think are scale. I can see white blobs of secretion everywhere over the tree, particularly concentrated where branches converge.

 

 

 

I’ve tried some systemic insecticide that is sprinkled over the soil at the base of the tree but it doesn’t seem to have stopped the spread. even the trunk at the base of the tree has some blobs already. Do I have any options or do I need to cut the tree down before it spreads?

  

 

[beexdee]

Also as an extra question, I have another 5 metre tall tree that’s about 5 metres away from this one which fruits. I can see some of the white blobs starting to form on its branches too and some leaves have pimples on them. I think it’s a Lilly Pilly as well based on the pink leaves at the branch tips. What should I do?

 

 

 

 

[EricL]

Hello @beexdee 

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

It does sound like your Lilly Pilly trees are dealing with a scale infestation. Since the systemic insecticide you applied at the base hasn’t been effective, you’ll likely need a more direct approach.
 

First, try spraying the trees thoroughly with an oil-based insecticide such as Eco-Oil, which will smother the scale. Please note that this is a concentrate and must be diluted before use. Make sure to coat both sides of the leaves, branches, and trunk. You’ll need to repeat this every couple of weeks until the infestation is under control. If the trees are too tall to reach the top branches, consider using a hose-end sprayer.

Since you have a fruiting tree nearby that’s also showing signs, act quickly to prevent further spread. Prune any heavily infested branches and dispose of them in the bin, not the compost. If ants are present, they could be protecting the scale, so applying an ant barrier such as Richgro 5kg Ant Killa Insecticide Granules around the trunks may help.

If the infestation is extreme and the tree is severely weakened, removal might be an option, but Lilly Pillys are tough and can usually recover with the right treatment. Keep an eye on new growth and be patient, as it can take a few months to fully get rid of scale.

Here is a handy guide that can help: How to diagnose a sick plant by @Noelle 

Please remember to wear personal protection such as gloves, goggles and a mask when using chemical sprays.

If you have any other questions we can help with, please let us know.

Eric

[beexdee]

Hi @EricL thanks for your helpful advice. 

We’ve gone ahead and pruned the worst of the infested branches and applied the eco oil spray as you suggested. 

I had a follow up question - the white blobs which are hard on the outside but soft on the inside, will not removing some of those shelter the scale insects from being affected by the oil?

I understand the oil functions by suffocating them, but if the insects are encased within the white secretions, will it still work? Or do I have to remove most of them for it to be effective?

I also ask as some of the treated branches for the larger tree are quite out of reach for pruning or manual removal so only the spray can reach without having to buy a ladder. 

thank you again

[JacobZ]

Hi @beexdee,

For areas that are in reach, you can use a small brush like a toothbrush to remove the waxy casing before applying your oil.

If applied in sufficient quantity, the oil will eventually suffocate any of the insects that remain in their waxy casing. This is a suitable method of dealing with them in areas that are out of reach. To increase the stick and spread of the Eco-Oil, you can also add some OCP Eco-Neem Concentrate to the mix. 

Ultimately, with enough applications, you should be able to control the insects that can cause damage. 

The waxy casings are not ideal for the plant, but unfortunately, you will need to manually remove them. Perhaps you could ask a neighbour, family member or friend if they have a ladder you could borrow for an afternoon to get the job done.

Let me know if you have any further questions.

Jacob

[matttheww]

hi why are the information you received so far? Is partly correct where you find most success is starting spraying from November to February when the scale is active throughout the rest of the year the scale is in the white protective facing and no insecticide pesticide or any spraying will affect it whatsoever. Manual removal well effective is often not practical You can try blasting them off with a high pressure hose and then spraying the ground thoroughly with a pesticide oil, however the only true method of removing them is spraying when active and don’t worry too much as they don’t cause terrible damage to the plant they just look unsightly

[JacobZ]

Hi @matttheww,

Welcome to the Bunnings Workshop community, it is wonderful to have you with us.

Thank you for sharing your guidance on how to address the scale issue in this post. We always welcome our members sharing their advice and experiences and are grateful when people take the time to do so.

Please allow me to tag @beexdee so they are notified of your comment. I am sure they will appreciate it.

Jacob