3 Types of Tree Insects and How to Get Rid of Them

Guest Post by Larry Taylor

If you have trees around your house it is likely that you will have more insects that could potentially get inside or cause other damage. While many insects live on and around trees without causing them much damage, there are some varieties of bugs that can be very destructive.

Most tree insects fall into the following three categories:

• Boring insects
• Chewing insects
• Sucking insects

To help you understand more about the dangers that these types of tree insects can cause, we’ve put together the following guide. Below, you’ll find a general description of each type of insect along with some example bugs and treatment methods for controlling them.

We hope to help you spot and resolve a tree insect problem before it’s too late therefore keeping the trees in your yard as healthy as possible.

Boring insects

The most harmful type of bugs in trees are those that bore. If left untreated the tree that has been infested will most likely die. This is due to the damage caused to roots, branches, and stems as the bugs dig tunnels through them, hollowing them out.

The most noticeable signs of boring insects are entry/exit holes in the bark, sawdust mounds near the base of the tree, and sections that are dying or falling apart.

Examples of boring insects

• Asian Longhorned Beetle
• Bronze Birch Borer
• Carpenter Ants
• Carpenter Bees
• Deathwatch Beetle
• Dogwood Borer
• Elm Bark Beetle
• Emerald Ash Borer
• Giant Palm Weevil
• Wood Wasps

How to control boring insects

Most boring insects only attack trees that are unhealthy. These include those that have been affected by improper irrigation, disease, or poor general care. Some invasive species of boring insects attack healthy trees as well.

Unfortunately, once a tree is infested with boring insects, there’s a low probability of saving it. The only thing you can do to improve the tree’s strength is to prune out the infested branches and/or try to treat it with an insecticide.

Quick pruning may require the use of a chainsaw or other common trimming tools. Chainsaws come in a variety of sizes. The best ones for pruning limbs and branches are those with a 12 or 14 inch blade. Larger chainsaw sizes (16 to 24 inches) are meant for cutting down trees or splitting firewood, so you can get away with a smaller and cheaper model.

Methods for controlling boring insects include the following:

• Irrigate trees properly based on their species.
• Avoid pruning trees when boring insects are flying around (i.e. late winter through late summer).
• Use a pruning sealer to protect the open wounds of a tree after pruning branches.
• Monitor tree trunks and branches regularly to detect infestations before they become serious.
• Use a tree injection kit to apply insecticide directly into the trunk of the tree. This helps to slow the damage down by boring insects and prevent them from entering into the tree.
• Apply a soil drench around the base of the tree in the early spring or fall so that the tree can be protected before the growing season.

Chewing insects

Chewing insects either attack the foliage or fruit of their target trees. While minor defoliation is often not a problem with healthy trees, repeated offenses can have more dramatic effects.

Usually, chewing insects are the culprits of degrading the appearance of a tree while no major structural harm is done. However, if a severe infestation or repeated attacks do occur, then it can weaken the tree or kill it.

Examples of chewing insects

• Apple Maggots
• Bagworms
• Cankerworms
• Caterpillars
• Cherry Fruit Worms
• Cutworms
• Gypsy Moths
• Japanese Beetles
• Leafminers

Controlling chewing insects

The best way to control chewing insects is to put up a barrier around the tree trunk or between leaf stems and limbs. That way these insects can’t access the leaves or fruit.

Examples for controlling chewing insects include the following:

• A tree band wraps around the tree trunk and acts as a barrier to stop chewing insects from climbing the tree.
• Annual tree care kits not only help boost the health of a tree but also helps trees resist the attack of chewing insects. These kits come in a combination of granular fertilizers and sprays.
• Injectable insecticides are deposited through holes that are drilled into the root flares of the tree trunk (i.e. where the trunk starts to flare out near the ground.)
• Soil drench insecticides are applied by mixing the pest control with water and then pouring the solution around the base of the tree. The tree’s roots take up the insecticide and distribute it throughout the tree trunk, branches, and leaves.
• Traps can be used to remove chewing insects without using insecticides. These are beneficial for fruit-bearing trees.

Sucking insects

Insects that suck on trees cause damage by removing the juices from leaves and branches. Repeated sucking causes the tree to dry out which, in turn, can cause leaves to fall and branches to weaken.

Instead of killing a tree directly, sucking insects reduce its growth rate which weakens the overall strength of a tree. Trees injured by sucking insects can be vulnerable to secondary insects or fungal diseases. Eventually, if not stopped or treated, these trees will die.

Sucking insects are relatively immobile creatures and just live on the outside of the tree on the branches. Signs of sucking insect infestations include scaly formations on branches, dieback of leaves, and honeydew production.

Examples of sucking insects

• Aphids
• Lace Bugs
• Leafhoppers
• Mealybugs
• Scale Insects
• Spider Mites
• Thrips
• Whiteflies

How to control sucking insects

Sucking insects are relatively easy to control. You can either use preventative methods to keep them away from your trees or kill existing infestations on contact.

Examples for controlling sucking insects include the following:

• Topical repellents to prevent sucking insects from latching onto the tree.
• Annual tree care kits to help maintain the health of the tree so it does a better job or resisting sucking insects. These kits come in a combination of granular fertilizers and sprays.
• Insecticidal soap is sprayed onto the tree and is a low-toxicity bug control solution favored by natural and organic gardeners.
• Any generic pest controls found at your local hardware or grocery stores. 

The importance of prevention

As you learned in this guide, there are three types of insects that can be potentially lethal to the trees in your yard. Fortunately, just because these insects exist and may be prevalent where you live, this doesn’t mean that all of your trees are doomed. 

If you need help getting rid of these pests, you can look into hiring a pest control company to come and help you. A number of pest control service providers offer specific services to help keep your yard pest-free. For help finding the best pest control company for you, see companies and customer reviews here. 

Keep an eye on the health of your trees and provide some annual preventative maintenance. Doing this will help you spot and stop the majority of these insects before they become a problem.

Larry Taylor is the man behind brand Chainsaw Larry and is passionate about helping people find the best chainsaws for their needs and teaching others how to keep their trees and yards in good shape.