Why Are There Insects Inside My Tree?

October 14, 2016 Blog Comments Off on Why Are There Insects Inside My Tree?

Insects In Trees

As a property owner, you should be taking the time regularly look at everything on your land, including your trees. It is common to notice insects on your trees every once in a while, but most people are surprised to see insects inside of their trees. This is unfortunately more common than you may realize and can indicate a serious issue that requires help from an arborist.

Understanding Why Insects Are There

Essentially, if insects are inside your tree, it is because your greenery is able to provide them with food and shelter. The exact nutritional needs of every insect are different and they are looking for different things. Remember that some insects are actually beneficial while others are harmful. Insects that are in your tree will be there because they are feeding on the leaves or searching for food and shelter within the trunks and bark. Since each insect has a different ultimate goal you will need to figure out which type of insect has invaded your tree to determine its purpose, whether it is harmful, and what to do about it.


These are among the most common insects to infest trees around the country and they can have a range of appearances. Aphids might be pale green, white, black, or pink and can be anywhere in size from that of a match head to that of a pinhead. They tend to cluster on young leaves, buds, and shoots. Aphids choose to go on your trees to suck the juices from stems and leaves. Unfortunately, aphids may even spread diseases.
Depending on the severity of the aphid infestation and the location of your tree, your arborist may suggest you let nature take care of them. After all, just a few of aphids’ predators include lacewing larvae, soldier and lady beetles, predatory midges, syrphid flies, parasitic wasps, certain birds, and lizards. You can also use insecticidal soap and a strong water spray in the case of more severe infestations.


Sometimes you will notice beetles on your trees since they like to feed on their leaves and those of shrubs. Some good signs of beetles or other leaf-eating insects are holes in the leaves or the edges of them disappearing. Remember that certain beetles are only active at night so they are harder to catch in the act.


While the majority of insects will stay on top of trees, there are certain types that actually go underneath the trunk and bark. Borers, for example, go underneath the bark, creating tunnels in the wood. They are fine if your tree is healthy, but those with a weakened system will fare worse if borers are also present. Borers in already sick trees can lead to branch dieback and wilting leaves along with early fall color or thinning foliage.
You know that borers are present if you find their emergence holes along the branches or trunk. The holes are frequently D-shaped and can be as small as a pinhole or as big as a quarter of an inch.


Mites will attack nearly any type of shrub or tree and your trees have a higher susceptibility if they are stressed. Since heat and drought are common stressors that can have a significant impact on the infestation risk, Texas residents need to be particularly careful to protect their trees from mites. You should also be careful with insecticides as using too much can increase the number of mites. Mites are most commonly gray, red, or black and tend to feed on the under portion of leaves. In most cases, mites will be controlled naturally via weather changes and predators, particularly on larger shade trees, but you should still consult an expert for help with your infestation.


Although scales are closely related to aphids, they have a shell-like covering that is waxy in nature. You can fight scales with lady beetles and other natural predators, frequent hosing, or handpicking them off. If you find scales on a deciduous tree in the winter, your arborist may suggest horticultural oil, which is also helpful against these insects while they are still crawlers.


Because thrips are microscopic insects, you may not be able to identify them by yourself. They will be on your tree in search of plant juices, leaf tissue, and flower tissue. They may spread plant disease, posing a risk to your trees. Although you can’t see thrips, you can look for signs of an infestation such as discoloration on the leaves and flowers, or them not opening normally or appearing twisted. The leaves may also become tan or silvery or you may notice the tiny fecal pellets.
As with other insects inside your tree, you can fight thrips with their natural enemies, which include minute pirate bugs, spiders, mites, predaceous thrips, and lacewing larvae. You can also use insecticidal soap.


Whiteflies are a type of small winged insect that will appear in clouds when touching an infected plant. You can typically tell that these insects have infested your tree by the yellow stippling that appears. If the whiteflies have progressed further, the leaves will curl and begin to turn brown as well.
When whiteflies are on your tree, this doesn’t automatically mean that the entire plant will have to be removed. It is sometimes possible to get them off with some help from lacewing larvae which are natural enemies of these insects. It is also an option to handpick the leaves that are heavily infested, use certain soaps, hose off the plant, or use sticky traps to catch them.

Other Insects That Live In Or On Trees

If you are concerned about insects that are living inside of your tree, then maggots, ants, or beetles may also be the culprits. These bugs may live in or underneath tree bark, but will typically not actually cause any harm. In fact, they are usually only present if the tree is already seriously sick or dying. If you notice chewing on the leaves of your trees, it may be due to a range of leaf miners and beetles, worms, moths, and caterpillars. Call San Antonio Tree Surgeons if we can answer any questions for you.

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