As invasive species continue to threaten native trees across the U.S., one pest in particular has tree care professionals and homeowners on high alert: the Asian Longhorned Beetle. Originally from Asia, this destructive insect targets a wide variety of hardwood trees, including maples, elms, willows, and birches. With the potential to cause severe damage and even tree death, it’s crucial to take proactive steps to prevent Asian Longhorned Beetle infestation, especially in the greater St. Louis area, where many vulnerable tree species are common in both urban and suburban landscapes.

What Is the Asian Longhorned Beetle?

The Asian Longhorned Beetle (Anoplophora glabripennis) is a large, glossy black beetle with distinctive white spots and unusually long antennae banded in black and white. Adult beetles can grow up to 1.5 inches in length, and they are most active from late spring through early fall.

Unlike many other invasive pests that feed on leaves or sap, beetle’s larvae burrow deep into the heartwood of trees. This internal feeding disrupts the tree’s vascular system, weakens structural integrity, and eventually kills the tree. Once infested, trees typically cannot be saved, which is why it is so important to focus on prevention.

Signs of an Asian Longhorned Beetle Infestation

Knowing what to look for can help you spot the problem before it’s too late. Key signs include:

• Round exit holes in the trunk or branches, roughly the size of a pencil
• Shallow, oval depressions in the bark where adult females have chewed to lay eggs
• Sawdust-like material (frass) at the base of the tree or in branch crotches
• Dead or dying branches, especially in the upper canopy
• Presence of the beetles themselves, especially in late summer

Because these symptoms can be subtle, and as Asian Longhorned beetle activity is often hidden inside the tree, early detection by a trained professional, specifically a certified arborist, is essential.

Trees at Risk in the St. Louis Area

While Missouri is not currently experiencing a widespread outbreak, the state’s abundance of vulnerable hardwoods, especially in the St. Charles and St. Louis metro areas, makes early prevention critical. The beetle has already caused extensive damage in states like Ohio, Massachusetts, and New York, and accidental introductions are always a concern in high-traffic regions like ours.

Some of the most commonly affected species found throughout St. Louis County, St. Charles, Chesterfield, Kirkwood, and O’Fallon include:

• Maple (particularly sugar, red, and Norway maples)
• Elm
• Birch
• Willow
• Horse chestnut
• Poplar

If your property in the greater St. Louis region includes any of these trees, it’s especially important to stay vigilant and take measures to prevent Asian Longhorned Beetle infestation before it starts.

How to Prevent Asian Longhorned Beetle Infestation

While there’s no chemical cure for Asian Longhorned Beetle infestation once a tree is infested, there are several proactive strategies you can implement to protect your trees:

1. Schedule Regular Tree Inspections

Certified arborists, like those at Hansen’s Tree Service, are trained to spot early signs of infestation that the average homeowner might miss. An annual inspection can make all the difference in catching problems early, before they become costly or irreversible.

We serve the entire St. Louis metro area, including St. Charles, West County, St. Peters, and surrounding communities, so no matter where you’re located, expert help is just a phone call away.

2. Don’t Move Firewood

Asian Longhorned Beetle larvae often travel unseen inside firewood. Transporting firewood from one region to another is one of the main ways the beetle spreads. Always buy firewood locally and burn it where you buy it, especially when camping or landscaping in areas where hardwood trees are abundant.

3. Maintain Tree Health

Healthy trees are better able to resist pests and disease. Keep your trees in top shape with proper pruning, mulching, watering, and fertilization. Prevent soil from compacting  by aerating it and keeping vehicles and heavy equipment off soil, mechanical damage to tree trunks, and other stressors that weaken trees and make them more vulnerable.

4. Report Any Suspected Infestations

If you suspect a tree may be infested with ALB, report it immediately to the Missouri Department of Agriculture or USDA. Early detection and swift action can help contain the threat and protect other trees in your neighborhood, whether you’re in St. Louis city or county, the Metro East, or anywhere through eastern Missouri.

Partner with Local Experts to Protect Your Landscape

When it comes to preserving your trees and maintaining a safe, healthy landscape, knowledge and vigilance are your best defenses. At Hansen’s Tree Service, we specialize in diagnosing tree pests and diseases and developing proactive care plans that help homeowners and property managers prevent Asian Longhorned Beetle infestation before it takes root.

Our certified arborists understand the unique risks facing trees in the St. Louis region and provide tailored recommendations to keep your trees strong, healthy, and beautiful year-round.

Don’t Wait for the Beetle to Show Up, Act Now!

If you have hardwood trees on your property, now is the time to act. Schedule a professional tree inspection with Hansen’s Tree Service today and let our experts help you prevent Asian Longhorned Beetle infestation before it’s too late. Call us or request a consultation online, your trees will thank you!