Protect Your Ash Trees from Emerald Ash Borer Infestation

Signs, Symptoms, and Treatment Options

Ash trees are a vital part of Colorado’s natural beauty. They provide shade, support wildlife, and produce valuable timber. However, these trees are under serious threat from emerald ash borer infestation (EAB), an invasive beetle that has already decimated ash tree populations across the United States. If left untreated, EAB infestations can destroy entire communities of ash trees, impacting both the environment and property owners. The good news is, with early intervention and the right strategies, you can protect your ash trees from this destructive pest.

What Is the Emerald Ash Borer?

The emerald ash borer (Agrilus planipennis) is a highly destructive beetle native to East Asia. It was first detected in the United States in Michigan in 2002 and has since spread to over 35 states, including Colorado. This invasive pest specifically targets ash tree species such as white ash, green ash, and black ash, causing widespread destruction wherever it spreads.

The lifecycle of the EAB consists of three main stages:

• Eggs: Female beetles lay eggs on the bark of ash trees. These eggs hatch into larvae. 
• Larvae: The larvae, which are worm-like, burrow into the tree under the bark. They feed on the nutrient-rich layers, cutting off the tree’s ability to transport water and nutrients. 
• Adults: In late spring, metallic green beetles about half an inch long emerge from the tree, leaving small, D-shaped exit holes in the bark. These adults then repeat the cycle by laying more eggs on nearby ash trees.

The damage caused by EAB larvae is what makes this pest so devastating. By disrupting the tree’s internal nutrient and water systems, emerald ash borer infestation leads to rapid tree decline and eventual death. This is why it’s considered one of the most serious threats in urban forestry. If you’re wondering what to expect from your trees this year, check out our 2024 tree care forecast.

Spotting Ash Trees on Your Property 

Protecting your trees from emerald ash borer infestation starts with knowing if you have ash trees. Here’s what to look for: 

• Leaves: Ash trees have compound leaves, each with 5–9 leaflets that are oval and pointed at the tip. 
• Branching: Look for opposite branching, where branches and buds appear in pairs directly across from each other. 
• Bark: On older ash trees, the bark creates a distinctive diamond-shaped pattern. Younger trees have smoother bark with less texture. 
• Seeds: Ash trees produce samaras, which are winged seeds that spin like tiny propellers when they fall. 

Not sure if your trees are ash? A certified arborist can help you identify them and assess for any early warning signs of emerald ash borer or other threats to your landscape.

Signs of an Emerald Ash Borer Infestation

Detecting an emerald ash borer infestation early is critical for saving your ash trees. Here are the key signs to watch for:

1. Woodpecker Damage: Woodpeckers feed on EAB larvae. If you notice light or discolored patches on the bark, it could indicate woodpeckers hunting for larvae. 
2. Canopy Dieback: One of the earliest signs of infestation is the death of branches at the top of the tree. Over time, this dieback spreads throughout the canopy. 
3. D-Shaped Exit Holes: As adult beetles emerge, they leave small, D-shaped holes in the bark. 
4. Sprouting: Infested trees often try to compensate for damage by producing new shoots on the trunk or lower branches. 
5. Cracked Bark: Splits in the bark may reveal the larval tunnels beneath. 

Smaller trees can succumb to emerald ash borer infestation within 1–2 years, while larger trees may take up to 4 years. However, the longer an infestation goes untreated, the harder it becomes to save the tree. If you’re unsure whether EAB or another issue is affecting leaf growth, check out our article on why your trees aren’t leafing out yet.

Why Infested Ash Trees Are Dangerous & What You Can Do for Protection

An infested ash tree is not just unhealthy, it’s also a safety hazard. As the tree’s structural integrity weakens, it becomes more prone to dropping branches or falling entirely. This poses a serious risk to people, property, and infrastructure nearby. Additionally, the removal of large, infested trees can be expensive, making early detection and treatment all the more important.

Protecting your ash trees from EAB starts with proactive measures. Here’s what you can do:

1. Learn to Identify EAB Signs: Familiarize yourself with the signs of an infestation so you can act quickly. 
2. Monitor Your Trees Regularly: Inspect your ash trees for signs of EAB damage, especially during the spring and summer when adults are active. 
3. Consult a Certified Arborist: Professionals can assess the health of your trees and recommend the best course of action. 

How Knothead Tree and Lawn Care Can Help in and Around Castle Rock, CO

At Knothead Tree and Lawn Care, we understand how devastating an EAB infestation can be for your property. Our team of ISA-certified arborists specializes in diagnosing and treating emerald ash borer infestation, helping preserve the health and safety of your trees.

Here’s how we can help:

• Preventative Treatments: We offer professional-grade treatments designed to protect healthy ash trees from EAB. These treatments are most effective when applied before an infestation takes hold. 
• Tree Removal: If a tree is already infested and beyond saving, we can safely remove it to prevent further spread of EAB and eliminate safety risks.
• Expert Advice: Not sure what to do with your ash trees? Our team can provide personalized recommendations to protect your property and maintain its value.