How to Get Rid of Bark Beetles: A Complete Guide 
Last modified on: September 6, 2021
Trees are an important part of the ecosystem. They’re also a critical part of your home’s landscaping, and you worked hard to plant and maintain yours. Suddenly, though, you notice that your trees are looking a little less than healthy.
There are holes in the trunks and branches, and the tree has started to drop leaves or turn brown. You’re worried you may have bark beetles, and you’re wondering what to do about it.
Fortunately, you’ve come to the right place. Here at Smith’s Pest Management, our team of certified horticulturists and arborists help prevent and get rid of the California bark beetle as part of our tree disease prevention services. We can help you resolve your infestation quickly and completely.
In this post, we’ll discuss what brings bark beetles to your trees, how to get rid of them, and when to call the pros.
Let’s dive in.
What are Bark Beetles?
Bark beetles live under the bark of trees, where they reproduce, nest, and eat. Bark beetles bore through the protective outer bark of a tree to lay their eggs in the inner bark layer.
These beetles and the larvae they produce feed on this living tissue, cutting off the tree’s ability to transport nutrients.
There are about 600 species of bark beetles in the US, most of which have evolved with their host trees over millions of years.
While most bark beetles affect dead or dying trees, some species - including the mountain pine beetle - attack living trees.
In fact, mountain pine beetles have killed 100,000 square miles of trees throughout North America over the last two decades. These beetles can be devastating for forests and landscape trees alike.
Bark beetles are a native species in US forests, but they can cause extensive tree damage when their numbers spike to critical mass levels.
In recent years, climate change has enhanced the damaging impacts of bark beetles, and led to significantly more bark beetle damage in US forests.
How to Identify Bark Beetles
What do bark beetles look like? Bark beetle adults are small, cylindrical, hard-bodied insects that tend to be roughly the size of a grain of rice. Most species are black, brown, or dark red in color.
They have visible antennas with large, clublike ends. Bark beetles have sturdy mandibles designed for chewing, and their larvae are grublike with dark brown heads and off-white bodies.
California bark beetles are similar in appearance to other bark beetles, with hard black bodies and obvious antennae.
Why are Bark Beetles Attacking My Tree?
To date, bark beetles have killed more than 102 million trees in California. People who understand how problematic bark beetles are may wonder what eats a bark beetle.
While bark beetles do have several natural predators, including woodpeckers, snakeflies, parasitic wasps, and other beetles, these predators are rarely present in large enough numbers to control the beetle.
Here are a few things that attract bark beetles to trees:
- Stressed trees. When their preferred food sources are available, bark beetles reproduce rapidly. Typically, bark beetles feed on trees that are stressed by drought conditions, or which are injured or diseased. These trees are easy for the bark beetles to infiltrate, and quickly become targets for these pests.
- Safe habitat. Bark beetles rely on the bark of trees to complete their life cycles. Adults bore into a tree’s bark to deposit their eggs in the inner layer. When the eggs hatch, the larvae eat the inner bark and continue tunneling inward, cutting off nutrients and killing the tree.
- Season. Beetles are the most active in the warm spring and fall days, and throughout the summer.
The next question, for many people, is what kinds of trees do bark beetles kill?
Bark beetles attract a variety of trees, including cedar, fir, pine and spruce trees. Sometimes, certain species of bark beetles will attack cypress, elm, arborvitae, larch, fruit, or redwood trees, as well.
Most bark beetles prefer stressed, sick trees. In addition to being easy to bore into, stressed or weakened trees don't produce ample sap, which pushes bark beetles out and keeps them from depositing eggs in the tree.
3 Signs of a Bark Beetle Infestation
The indications of bark beetle damage are obvious. Here are a few of the most reliable bark beetle signs:
- Pitch tubes. Healthy trees react to bark beetle attacks by releasing pitch. This response leaves small white or brown pitch tubes on the outside of the bark, which look like ½-¾ inch blobs of sap. White pitch tubes mean the tree resisted the attack, while reddish-brown tubes mean the beetle successfully attacked the tree.
- Holes in the bark. Pitch tubes will be accompanied by sawdust-like substances created by bark beetles and their larvae as they bore through the bark. Bark flaking, which builds up on the ground, is also a good indicator that beetles are present.
- Browning needles. The needles on conifer trees will turn reddish-brown during a bark beetle infestation. The color typically starts at the top of the tree, and movies down as the infestation gets worse.
How long does it take for bark beetles to kill a tree? The answer varies. During the warm summer months, bark beetles can kill a tree in just 2-4 weeks, although the process can take months or more.
How to Get Rid of Bark Beetles: 3 Critical Steps To Take Right Now
The sooner you get rid of beetles, the better the chances of saving your tree. Here are three important steps to take right now:
1. Apply a sylo insecticide
Sylo Insecticide is a synthetic, long-lasting systemic insecticide for pine bark beetles. The pesticide is made up of the active ingredient Cypermethrin, and is an excellent insecticide for both preventing and resolving bark beetle infestation.
As with most bark beetle infestations, timing is key. The insecticide is more effective if you apply it early in an infestation. For best results, spray the insecticide on the bark, trunk, branches, and twigs of the affected tree. Spray any obvious bark beetle holes directly with the pin stream setting on the applicator.
Be careful when applying the pesticide. Wear personal protective equipment (PPE) and always follow the manufacturer's directions exactly.
2. Prevent future infestations
Once you’ve sprayed the tree with insecticide, the next step is to maintain your trees and property to resist further pest infestation.
Here’s what we suggest:
- Apply prophylactic doses of insecticides every few months. This prevents bark beetles from penetrating the bark and laying eggs, and helps healthy trees stay that way.
- Give the tree ample fertilizer and water to help it stay healthy and strong.
3. Work with professionals
The best way to resolve existing bark beetle infestations and prevent new ones is to work with a professional like Smith’s Pest Management.
Our team will evaluate your property, make recommendations for your unique infestation, and help deliver a solution that gets rid of bark beetles for good.
How do Certified Arborists Get Rid of Bark Beetles?
Here at Smith’s, we focus on prevention, but also treat the root of the bark beetle problem - starting with the tree itself.
Here’s the process we follow for bark beetle treatment in California:
First, we inspect the tree and all the surrounding trees for signs of beetle infestation, which includes little bits of sawdust or bleeding liquid from bore holes.
We also interview property owners to learn about the history of the site, if there's been any heavy excavation of any kind around the tree, if there was a source of water that was cut off, or if there’s anything else that could be causing the tree to suffer from stressors that make it more susceptible to the beetles.
It's important to note that, in nature, these beetles don't attack healthy trees. Usually, healthy trees can defend themselves. We believe our role is to help healthy trees boost their natural defenses, and to provide additional defenses for sick or compromised trees.
Next, we measure soil moisture and prescribe careful rounds of recovery irrigation cycles to restore the soil moisture. From there, we apply certain systemic insecticides into the wood of the tree when appropriate.
If there's a secondary fungal or bacterial infection, we treat that with the antibiotic or fungicide when appropriate.
3. Soil amendments
Finally, we prescribe and treat the soil with biostimulants and surfactants, weeding agents, and slow-release fertilizers. To maintain the soil, we cover it with two inches of natural mulch. The tree should then be watered once per month until the winter rainfall returns.
Finally, we monitor the tree’s health over time. We’ll make amendments as needed, depending on the tree’s health and future infection risk. Our drought-proofing services will help strengthen your trees and keep your landscaping beautiful for years to come.
How to Stop Bark Beetle Re-infestation: 3 Important Tips
Stop bark beetles from coming back into your landscaping with these tips:
- Prune dead branches. Dead branches should be pruned out as soon as possible whenever they occur. This should be done by a certified arborist with a good reputation in the area.
- Remove wood and other hiding places. Do not stack fresh chopped wood around the trees or keep wood piles in your yard. If you want to keep wood as firewood, it should be left out in the sun to dry and “season.” Seasoned firewood is dried and free of pathogenic insects. Freshly-cut firewood, on the other hand, can continue to host pests and re-infect other trees nearby.
- Know the signs. It's important to note that if an oak tree is dripping a dark sticky substance on the ground, this isn't a bark beetle most of the time. Most of the time this is a filbert weevil which is attacking the acorns of the tree. This infestation is benign and not treatable. Wash the sticky substance away when it occurs, and wait for the tree to drop the acorns at the turn of seasons.
Can Bark Beetles infest Homes?
Theoretically, bark beetles could make their way into homes. Since beetles feed on wood, and homes are made of wood, they can cause damage to building materials.
If you have current bark beetle infestation in your home, spot treatments are an effective way to get rid of the beetles. Contact Smith’s Pest Management to learn more.
Are Bark Beetles Destroying Your San Francisco Bay Area Trees? We’re Here to Help!
You don’t have to live with bark beetles in your home or around your property. Here at Smith’s Pest Management, we help residential and commercial properties in Northern California - from Marin to Monterey - learn how to get rid of bark beetles.
Contact us today to learn more about our services or to get a free quote today.
Author Bio: Zach Smith
Landscape Pro Turned Gopher Pro: Owner, Zach Smith, graduate of Cal Poly’s Horticulture program worked nine years as a landscape professional- dealing with gophers, moles, and ground squirrels and was quickly recruited by other local gardeners. Fast forward to the past 10+ years, where Zach and his team trap and remove burrowing pests from residential, municipal and commercial properties throughout the San Francisco Bay area, from Marin to Monterey.
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