Best product for bugs that are eating the new growth and soot on lilly pillys?
Hi @rosey55,
You might like to have a read through of this guide: How to diagnose and revive a sick lilly pilly.
That’s usually caused by psyllids or scale insects feeding on the new growth. The black soot is sooty mould growing on the sticky honeydew they leave behind.
A good treatment is spraying with https://www.bunnings.com.au/ocp-750ml-ready-to-use-eco-oil_p2961639 , making sure to coat the new growth and undersides of the leaves well. You may need a couple of applications a week apart.
Also prune off the worst-affected growth and dispose of it in the bin rather than composting. Once the pests are controlled, the sooty mould will gradually wash or wear off.
Just to clarify, these pests don’t actually chew the leaves, they’re sap suckers. They pierce the new growth and feed on the sap, which can cause distortion and damage, but not holes. If you’re seeing leaves being eaten, there may be another insect involved as well.
If you’re able to share a few photos, we can help confirm exactly what’s going on and whether there’s another pest at play. Please let me know if you have any questions.
Mitchell
Hi Mitchell with the bugs on the Lilly Pillys am I able to spray the trees when it is not raining? Every tree has been eaten, as soon as new growth appears they are being chewed. We have had mulch put down around them and I was wondering if this might have caused the issue.
Thanks for those images @rosey55, that really helps with identification.
Yes, you can definitely spray when it isn’t raining. In fact, you’ll get much better results applying Eco-Oil during a dry spell so it has time to properly coat the insects and foliage before being washed away. Try to spray in the cooler part of the day and avoid very hot weather.
The sooty mould and distorted new growth are one issue, and I’d still follow the Eco-Oil treatment advice above for that, as it’s most likely caused by psyllids or scale insects.
However, the chewed leaf edges are caused by something different. The damage looks much more like chewing insects such as caterpillars or beetles feeding on the soft new growth. Lilly pilly beetles and night-feeding pests are fairly common.
The fresh mulch itself usually doesn’t cause the problem, but it can create a more sheltered, damp environment that some insects like to hide in during the day.
You could try checking the plants at night with a torch, as many chewing pests feed after dark. If you spot caterpillars, you can treat them with https://www.bunnings.com.au/ocp-40g-eco-caterpillar-killer_p0712284?msockid=03fc5caf25bf6f4132834be3245f6ed2 . If you do find beetles, then it would be best to reach out to an arborist/tree doctor, as they will have access to suitable treatments. Alternatively, you can try picking them off and dropping them in a bucket of soapy water.
Keeping the plants healthy through regular feeding, which encourages fresh growth, will also help them recover fairly quickly once the pests are under control. Let me tag one of our knowledgeable horticulturalists @Noelle to see if they have any thoughts.
Hi @rosey55
I agree with everything Mitchell has said! The Eco Caterpillar is the most appropriate form of pest control to use in cases like yours. Once the caterpillars, scale and other pests have been cleared up, the sooty mould will disappear. It's a mould that grows on the sticky secretions of other pests like aphids and scale.
