Pests – everyone hates them. They ravage and destroy your plants and trees. Annoyingly, they can be pretty tricky to get rid of without the right equipment. Let’s find out how to get rid of bugs on a bonsai tree.
Bonsai can suffer from many common pests, such as aphids, spider mites, scales, and vine weevils. They all manifest in different ways, but they can all harm your tree if left untreated.
Below are some common pests and how you can treat them:
Aphids typically appear as small black insects, bunching together and excreting ‘honeydew‘ a sticky and shiny substance which is left on the leaves. They are pretty easy to treat and won’t do much harm to your tree, but it’s better to get rid of them as soon as possible.
To get rid of aphids, you should use an insecticide. This can either be a commercial chemical one or a homemade one. I prefer to use homemade ones made of water and dish soap, as this has proven quite effective at killing and preventing aphids. However, you can still use chemical pesticides – beware that this can harm any other insects visiting your tree, such as pollinators.
You can also pick off the aphids from your tree. However, this might take a bit longer. If you use this method, you should also check that more don’t hatch. Otherwise, it’ll be a continuous cycle of picking!
2. Spider Mites
Spider mites are identified by little yellow specks on leaves. They usually are an oval in shape, with their eggs scattered around on the leaf. They can be pretty hard to spot, but a method of identifying them is to place a piece of white paper under the leaves and flick them. They should fall onto the paper, allowing you to identify them.
Again, you can use the insecticide method to eliminate spider mites. Spider mites can be a bit more harmful than aphids, so watch out!
Thrips are generally tiny and speckled, you’ll find yellow spots on leaves. The metallic sheen can also identify them on leaf surfaces. Adult thrips have wings and can fly but larvae look similar.
4. Fungus Gnats
Fungus gnats look like small gray flies flying around your bonsai tree. If they come out of the soil, they are most likely fungus gnats.
A watering issue usually causes gnats – if you’re overwatering your tree, this can lead to a gnat infestation. To treat this, you can let the soil dry out a bit, encouraging them to leave. However, don’t let the soil dry out all the way; otherwise, this can kill the roots and the tree very quickly.
5. Vine Weevils
Vine weevils are about 10mm long, with cream bodies and brown heads. They can affect the root system of a tree quite severely. They cause irregular notches on the edges of leaves. The larvae will consume the root system, with the majority of damage showing in autumn to spring. Chances are, if you’re thinking about how to get rid of white bugs on bonsai trees, you most likely have vine weevils.
You can get rid of vine weevils by physically removing them or using insecticide. Nematodes will also work as a biological control, and there are some specifically for vine weevils which you can buy for a low price.
Frequently Asked Questions (FAQ)
How can I prevent pests?
Pests can usually be prevented through good care. However, some will attack regardless. You can use an insecticide sprayed every few weeks as a preventive method. However, you should limit this as the chemicals could affect the environment, especially wildlife. While doing this, you should ensure that you don’t stress out the tree from things such as overwatering, underwatering or excessive pruning. This can encourage pests to attack the tree.
Are there any organic pesticides?
Neem oil is an excellent organic pesticide, which has proven to be quite effective at removing pests and some fungi problems such as black spots. It can be found relatively cheap online, and many bonsai practitioners and gardeners use it quite frequently. It’s a great alternative to chemical pesticides.
How do I prevent pests in winter?
In winter, I usually give my trees a wipedown of lime sulfur, which acts as an insecticide and a fungicide. This helps to remove any pests or diseases which have been overwintering themselves on the tree, hoping to do more damage come spring time. It can be bought for a low price and is very economical, so you won’t have to purchase any more for a while. You should be careful with it, though – wearing gloves and avoiding contact with your skin. If you swallow it or get it in your eyes, you should consult a doctor immediately.