First time poster, hoping to get some assistance identifying a potential disease. I have a number of Lilly Pilly screening trees at my house and have noticed that the leaves have started turning purple/brown. Upon further investigating, I've since noticed there is a lot of white mould-like patches on the underside of the leaves and have become quite concerned for the health of the trees.
I have attached a number of images showing the issues. Any help identifying the issue and how best to remedy it would be greatly appreciated!
Welcome to the Bunnings Workshop community @AzzaJ. It's fantastic that you joined us, and many thanks for your question on Lilly pilly diseases.
As far as Lilly pilly trees go, yours is looking quite healthy as they can be susceptible to many diseases. Normally when someone is asking for assistance, there are several issues to deal with. I'm actually not sure what the dark speckling is on the leaves. If it were powdery, it would be sooty mould, but this doesn't really look like that. Let me mention @Adam_W and @mich1972 to see if they had some ideas.
Hi @AzzaJ and welcome.
Okay, this one has me a bit perplexed.
Let's unpack all this a little...
The leaves with the brown/red patchiness... that looks to me like some form of damage from insects. Possibly thrips or mites, the bugs that are on the smaller side.
Interesting that the new leaves are perfect so maybe the pests have finished their season? Are there any bugs or marks visible under the leaves that are discoloured?
Now, that white patchiness. Hard to tell without a serious close-up photo but they actually look like they might be clusters of really tiny eggs. Is that possible?
Does the white stuff brush off? If so is it dusty, meaning only husks are left, or is there moisture there, meaning the eggs are active?
Not much help at this stage but let's see where we can get to.