Most Common Tree Diseases & Bugs – Ultimate Guide

When you own trees it is your responsibility to learn how to look after them. To observe signs of tree diseases and tree insect pests, and to do what you can to prevent it, heal it, or remove it. Obtaining an arborist report can help identify necessary mitigation measures. Tree pests and diseases can damage all of the tree, from the roots to its trunk and branches to the shoots and leaves. They can also spread to other trees. The tree can start to look sick, if it is a fruit tree it stops yielding. It helps to know a little about current tree diseases and common tree bugs. It also helps to refer to tree pests and diseases pictures online. Have a reputable professional tree service with an Arborist who knows all about tree diseases and pests.

Most Common Tree Diseases, Bugs and Pests

Just as you take care of your plants so too should you be taking care of your trees in case of tree diseases. Even established trees thrive and do better. They live longer and are less likely to spread tree diseases and pests to other trees and plants around. While some tree bugs, Australia specific, are fine and even offer benefits to the trees, there are some common tree bugs that are more like pests. A diseased tree or one with a tree fungus, is weakened and is a danger.

It is in an owner’s best interests to have a better understanding of tree fungus, current tree diseases and tree insect pests. As well as exploring information and taking a look at tree pests and diseases pictures, the information here can help you. Some common tree pests and diseases and tree fungus in Australia include;

• Brown root rot
• Christmas beetle
• Cigarette beetle
• Giant wood moth
• Leaf beetles
• Common furniture beetle
• Termites
• Sirex wood wasp
• Lerps and psyllids
• Kirramyces leaf diseases
• Erinose mite
• Five spined bark beetle
• Giant wood moth
• Gum leaf skeletoniser
• Lesser augar beetle
• Quambalaria shoot blight
• Pine bark anobiid
• Longicorn borers
• Scarab beetle
• Powderpost beetle
• Pink disease
• Plate galler
• Queensland pine beetle
• West Indian drywood termite

How to Identify Tree Diseases

In order to correctly make any tree infestation identification, you need to do some research. It is also a good idea to talk to your tree services and ask them for ideas on how to identify tree disease. The disease can spread and lead to a loss in crops, other trees and plants. Diseases can be seasonal, species-specific and regional too.

How to Treat Tree Diseases

If you do have a diseased tree or problems with tree pest control, there are different approaches to take for treatment, depending on the tree, the issues and the time of year. This way when you are looking at how to get rid of tree fungus or treat a disease you know the best approach. Often you need to remove dead branches, leaves and twigs and then apply the right kind of fungicide. For the best guidance on how to treat tree diseases it’s best to call in a professional.

How to Tell When a Tree is Dead?

You need to know the difference between a sick tree and one that is dead. Sometimes sick trees can be saved with the correct approach but a dead tree cannot and this is one of the reasons to remove a tree. How to tell when a tree is dead is seeing mushrooms growing near the roots, peeling and cracked bark and a lot of branches that no longer have living buds. When you scratch a twig with a knife a healthy living tree will be green and moist underneath. Brittle and brown indicate a problem and you need to call an arborist. They can best judge how to identify a dead tree. One of the big tree removal reasons is when a tree is diseased or dead. Otherwise, it attracts pests, spreads disease and can hurt other living things around it, as well as being a danger.

Tree Diseases, Bugs and Pests by Tree Type

Here is a look at different common tree types in Australia and different tree fungus, tree pests and diseases that might affect them.

1) Citrus, Lemon Tree Pests and Fruit Tree Diseases

Being able to plant and grow citrus trees can be very rewarding. But sometimes even with the best care things happen. There are a lot of citrus tree pests and diseases that can affect your fruit trees. Knowing what to do including ideas about organic pest control for fruit trees can really help. Here is a closer look at some of the more common pests on citrus trees as well as fungi and diseases things, as well as ideas about fruit tree pest control and treatment.

• Lemon trees – There are a few diseases and common lemon tree pests. Scab disease causes spots on both the fruit and the leaves and produces pustule-like growths. It thrives in moist conditions and treatment is usually a copper fungicide. Another disease in lemon tree diseases and pests is the citrus canker. Scabs form causing yellow lesions. When it is serious there is fruit drop and loss of leaves. It can be suppressed with liquid copper but a serious infection usually means the tree needs removing. A common lemon tree pests Australia is the citrus leafminer. Signs of this pest are silvery tunnels within the leaves. They are controlled with the introduction of another insect, the small parasitic wasp and damage areas pruned away.
• Orange trees – Greasy spot is another disease caused by a fungus. You will find blisters under the leaves that are yellowy-brown and then greasy-looking. It is a very damaging disease and requires collecting fallen leaves as well as spraying liquid copper. It can kill and lead to tree removal. The lightbrown apple moth is a pest that especially enjoys orange trees. Orange tree pest control includes introducing certain wasps and applying a mix of chilli, garlic and pyrethrins. Aphids are another of the types of pests on citrus fruit trees to look out for.
• Grapefruit trees – A common disease in grapefruit trees is Melanose. You will see small lesions on the fruit as well as spotting and pustules. Strong trees can fight it off. Dead materials need removing along with the use of liquid copper. More grapefruit tree diseases, pests and the like include citrus back spot and whiteflies. The latter pest looks like white moths. Check the underside of the leaves. Some natural predators are lacewing and ladybirds.
• Quince trees – You would notice sooty mould from the black effect on the leaves. As it grows it can become dense and spread. Quince tree pests and diseases can be controlled with prevention. Keep the whiteflies and aphids away and you can avoid sooty mould. Use an insecticide to treat pest problems and liquid copper for mould.
• Lime trees – Dark spots on your twigs and fruit could be anthracnose. This is one of the common lime tree pests and diseases. You might also see leaf dropping and fruit decay. Fungicide is applied to treat it but sometimes careful tree pruning in Perth is enough. Look out for lime tree pests Australia based such as scales. They seem to have no eyes or back legs. Some small wasps are their predators as are ladybirds and you can use horticultural oil.
• Nectarine trees – Finally we have nectarine tree pests and diseases. Phytophthora root rot is one to look for. You can see signs like yellowing leaves. Use careful immigration to handle it as well as strong fungicides. One of the pests you will see in fruit tree pests pictures is the Mediterranean fruit fly. Look for small holes in the fruit skin where the eggs are laid.

2) Birch Tree Pests and Diseases

Birch leaf spot is a disease that affects birch trees and spreads through tree fungus spores. Signs include small black spots that get larger and join together. Trees shed their leaves and over the years if untreated become prone to other Birch tree pests and diseases. A common pest is the bronze birch borer beetle. They affect sap flow which means the tree becomes malnourished. Only one in ten birch trees survive.

3) Fig Tree Pests and Diseases

Fig tree pests, pests that attack fig trees

When it comes to fig tree pests there are a few. The Queensland fruit fly is a small black fly recognizable with its yellow or cream markings. Fallen figs need to be thrown and pheromone traps are used to kill the males. Another of the pests is the fig blister mite. Clear to white mites that attack inside the fig fruit that leaves behind rusty coloured areas. Destroy damaged fruit. Two fungal diseases that affect fig trees are anthracnose and fig rust. Fig rust leaves yellow powdery spots and anthracnose causes small black or brown spots. Copper-based fungicides are used to treat it.

4) Mulberry Tree Pests and Diseases

Mulberry tree pests and diseases include two main diseases the bacterial leaf spot and fungal leaf spot. Both cause defoliation and both can occur at the same time. The leaf has spots and then slowly dies and then they spread. Rake up the leaves around it and make sure there is good airflow. Bacterial blight is more of a problem because it damages new leaves and shoots. Using a liquid copper fungicide is a good way to manage it.

5) Plum Tree Pests and Diseases

Plum tree pests, Australia and disease are pretty varied ranging from viruses, tree fungus, bacterial and pests too. It usually affects the fruit crop so prevention is best but if it happens it could be something like black knot plum disease. This starts out as a green knot that then swells and blackens. Black rot can spread to limbs and even the trunk of the tree. With pests, there is the plum curculio, a snout beetle. It can cause a lot of damage and leads to fruit dropping, scabbing and decay. The best solution is to spray with pesticides.

6) Wattle Tree Pests and Diseases

Wattle trees are quite an easy type of tree to grow but some of the things more likely to happen in terms of tree diseases and pests are borers, bag-shelter moths and galls. Borers are the larval stage of beetles and sometimes moths and they can tunnel into branches and the trunk. They can lead to eventual death and the removal of a tree. Look for sawdust material and oozing sap. Insecticides cannot reach them but sometimes you can prune away affected branches. Another of the wattle tree pests and diseases are Bag-shelter moths. At night they feed on leaves and can quickly strip a plant or tree.

7) Pine Tree Pests and Diseases

When looking at pine tree pests we have the five spined bark beetle identifiable by the blue stain fungi that it spreads. It is controllable with parasitoid wasps and good cultivation methods. Another of the pine tree diseases and pests are the pine bark anobiid. It damages timber as well as trees and can burrow for quite long distances.

8) Apple Tree Pests and Diseases

When looking at apple tree pests, Australia you will find the native budworm is one that hits them. These apple tree pests feed on the newly set fruit, the shoots and the flowers. The fruit drops which is why growers have to learn how to protect apple trees from pests like this. Usually, chemical control is not needed though and an apple tree organic pest control is effective. For help with apple tree pest identification talk to a fruit tree specialist. As well as needing apple tree pest control there are also a number of diseases that can affect them such as pink disease. It causes stem canker leading to sunken and swollen areas and split or cracked bark.

9) Cherry Tree Pests and Diseases

Cherry tree pests and diseases Australia cherry growers find are a constant problem they have to prevent, manage and treat. It really impacts cherry productivity as cherry tree pests eating leaves and causing damage drop the volume of viable fruit yields. As well as Cherry tree pests there are also diseases. Grey mould leads the fruit to grow a brown-grey mould on it, turning tan coloured as it ages.

10) Kowhai Tree Pests and Diseases

There are a few Kowhai tree pests and tree diseases but the more commonly known is the Kowhai moth that lays eggs on the tree and its larvae eat the seeds and leaves. There are also scale insects though these are easy to control with spraying oil throughout the year. The latest threat are Psyllid, which are jumping plant lice.

11) Palm Tree Pests and Diseases

With palm tree pest control you would be looking for the mealy bug, an oval pink, grey or yellow insect, just 2 mm long with a white wax coating. They breed very quickly and a colony can do a lot of damage unless controlled with pesticides. Even if on top of palm tree pests treatment there are always diseases and fungi to look out for. Damping off is one that happens to new seedlings grown in a greenhouse. It is important there is enough ventilation and fungicide sprays can treat it.

12) Avocado Tree Pests and Diseases

For avocado tree insect pests and diseases there are anthracnose and root rot and then the fruit spotting bug. Check with avocado tree pests identification experts to protect and look after your avocado trees. Root rot is a big problem caused by a soil-borne fungus. It requires proper root management and care.

13) Linden Tree Pests and Diseases

When it comes to current tree diseases and pests with Linden trees you have leaf spots and canker. Leaf spots are caused by different fungi and dealing with it means pruning and raking up and destroying affected leaves. Canker causes dead spots on your tree. When you see the damaged area prune them away well below the canker to where it is healthy still. If the canker is on the trunk then pruning is not possible.