TREE TRUNK BORING INSECTS
Insect Control for Trees
TREE-äge® Insect Control
Controlling certain insects can be quite challenging, particularly trunk borers. Fortunately, we have an effective solution called TREE-äge® (pronounced “Triage”). This specialized tree insecticide is injected directly into the trunk of the tree. TREE-äge® injections are recommended for trees that are suffering from damage caused by boring insects such as the Emerald Ash Borer, Rocky Mountain Pine Beetle, Lilac Borer, Pinyon Pitch Mass Borer, Peach Borer, Apple Borer, or Zimmerman Moth.
Trunk Injections
Trees That Need to be Treated Before an Attack
Emerald Ash Borer
Ash trees must be treated proactively before the Emerald Ash Borer (EAB) attacks because once an infestation begins, it is often too late to save the tree. EAB larvae burrow under the bark, disrupting the tree’s vascular system and cutting off essential nutrients and water flow, leading to rapid decline and death within a few years. Since symptoms may not appear until significant internal damage has already occurred, preventative treatment with systemic insecticides, such as TREE-äge (emamectin benzoate) or imidacloprid, is the only reliable way to protect ash trees.
Long Term Protection
These treatments provide long-term protection, allowing the tree to fight off infestations before they start. Without proactive care, nearly all untreated ash trees will succumb to EAB, leading to hazardous dead trees and costly removals. Early treatment is the key to preserving ash trees and avoiding devastating losses.
Trees That Can be Treated Reactively
Lilac / Ash Borer
Proactive treatments for lilac borers on ash trees are generally unnecessary because these borers primarily target weakened or stressed trees, especially drought stressed trees. Unlike the Emerald Ash Borer, which aggressively kills even thriving ash trees, lilac borers tend to infest trees that are already compromised due to drought, poor soil conditions, mechanical damage, or improper pruning. Maintaining proper watering, mulching, and overall tree health is usually enough to prevent infestations. Additionally, if an infestation does occur, localized treatment with insecticides like TREE-äge or permethrin can be applied only as needed, rather than using unnecessary preventative applications.
Zimmerman Moth
Preventative treatment for Zimmerman Pine Moth on Austrian pine trees is generally unnecessary because these trees can often tolerate minor infestations without significant long-term damage. Zimmerman moth larvae typically attack weakened or stressed trees, meaning that maintaining overall tree health through proper watering, mulching, and pruning is the best defense. Additionally, infestations tend to be localized, affecting individual branches rather than the entire tree, making targeted treatment more practical if damage is observed. Since Zimmerman moth populations can fluctuate and do not always cause severe harm, routine preventative insecticide applications are often unnecessary and may not be cost-effective. Instead, monitor trees for signs of larval activity (pitch masses at branch unions) and apply treatments of TREE-age only if damage becomes significant.
Pinyon Pitch Mass Borer
Reactive treatment for Pinyon Pitch Mass Borer focuses on stopping the active infestation and preventing further damage to the tree. Since these borers tunnel under the bark, trunk injections with TREE-äge (emamectin benzoate) are the most effective option, as they provide systemic control, killing larvae inside the tree and offering long-lasting protection. Additionally, bark sprays with permethrin or bifenthrin can help eliminate adult moths and newly hatched larvae when applied during their active periods in late spring to early summer. If infestations are localized, pruning and disposing of affected branches can reduce borer populations. Improving overall tree health is also essential, as stressed trees are more susceptible to attack—deep watering, mulching, and avoiding mechanical damage can help the tree recover and resist further infestations. Acting quickly with a combination of treatments is key to managing Pinyon Pitch Mass Borer infestations effectively.
Bronze Birch Borer
Other Pests That Can be Treated Reactively
- Pine Bark Beetles – Includes Ips, Mountain Pine Beetle, and Southern Pine Beetle, which tunnel under bark and disrupt tree function.
- Bronze Birch Borer – A major threat to birch trees, causing dieback and eventual death.
- Oak Borers – Various borer species that impact oak trees, leading to decline.
- Turpentine Beetles – Affects pine trees, causing sap leakage and structural damage.
- Bagworms & Caterpillars – Including Fall Webworm, Tent Caterpillars, and other defoliating pests.
- Leafminers – Insects that tunnel inside leaves, causing damage to foliage.
Learn How to Identify the Emerald Ash Borer
TREE-äge® Insect Control
Recommended Uses for TREE-age Tree Insect Treatment
- TREE-age is a wonderful tool for trees that are surrounded by rocks, patios, or are near water and cannot be treated via the soil drench technique.
- When a tree is under severe insect pressure from a trunk-boring insect. Note: The insect pressure needs to be severe enough that it might kill or damage the tree.
- If the tree is suffering from insect pressure from the following insects.
- Emerald Ash Borer (Treat proactively or re-actively once and it will control the insect for 2 years, then treat using Soil Injections every year moving forward) Note: EAB arrived in Colorado Sept 2013)
- Lilac / Ash Borer (Treat every 3 years, treat re-actively only as needed)
Mountain Pine Beetle (Treat every 2 years, proactively only as needed) - Pinon Pitch Mass Borer (Treat every 3 years, treat re-actively only as needed)
- Zimmerman Pine Moth )Treat every 3 years, treat re-actively only as needed)
Pricing for Trunk Injection using Tree-äge®
Tree Trunk Breast Height Diameter – Cost Per Tree
2-8″ – $137.00
9″ – $149.50
10″ – $162.00
11″ – $174.50
12″ – $187.00
13″ – $199.50
14″ – $212.00
15″ – $224.50
16″ – $237.00
17″ – $251.50
18″ – $264.00
19″ – $276.50
20″ – $296.50
21″+ – Call for Pricing
Discounts: 5% off between $200-$300, 10% off between $300-$500, and 15% off for $500+
Application Season
Ideal time for Preventative Treatment
Late May – Early September
Ideal time for Reactive Treatment
Leaf on to Leaf Off (Typically April-early October)
Schedule an Expert Tree Care Evaluation
Professional Tree Care Services
Choosing the right insect control for your trees can be challenging due to the different product functions. Contact our office today to consult with a tree care expert and get your questions answered.
Organo-Lawn of Boulder (303) 499-2000 or Fort Collins (970) 225-9425
Tree Trunk Boring Insect Treatment FAQs
How often does TREE-äge® need to be applied?
TREE-age will last in a tree for 2-3 years. We recommend an application every 2 to 3 years, depending on the tree species and the type of insect that we want to control or prevent.
How Long Does a TREE-äge® Trunk Injection Last?
1-2 Years
TREE-äge (emamectin benzoate) provides long-lasting protection once injected into a tree’s vascular system. The duration of its effectiveness depends on pest pressure, tree health, and environmental conditions.
- Up to 2 years of protection against wood-boring pests like Emerald Ash Borer (EAB), Bronze Birch Borer, and Pine Bark Beetles.
- 1-2 years of control for Zimmerman Pine Moth, Lilac/Ash Borer, and other borers.
- Typically lasts one full growing season for leaf-feeding pests like caterpillars and leafminers.
Systemic Insectide
Since TREE-äge is systemic, it moves through the tree’s vascular system, protecting current and future growth during this period. Reapplications are typically needed every two years for high-risk trees.
Additional Trunk Injection FAQs
Drilling small holes for Arborjet trunk injections does cause minor wounding, but when done correctly, it does not significantly harm the tree and is far less damaging than the effects of untreated pests or diseases. The holes are small, strategically placed, and designed to heal over time.
No; we leave the plugs in the tree.
The plugs used in trunk injections serve an important role in ensuring efficient insecticide delivery, reducing tree damage, and promoting healing. These small, specialized plugs are inserted into the drilled injection sites and remain in the tree after treatment.
The time required to complete this tree care service can range from 5 minutes to 8 hours. This duration depends on several factors, including the health of the tree, the moisture level of the soil, and the outside temperature. In cases where the tree is absorbing water very slowly, we may leave the equipment connected and return the next day to retrieve it.
Once TREE-äge is injected into a tree, the time it takes for the insecticide to fully distribute through the vascular system depends on several factors, including tree size, health, and environmental conditions.
Estimated Uptake Time
- Small Trees (5-10 inches in diameter): 2-4 weeks
- Medium Trees (10-20 inches in diameter): 4-6 weeks
- Large Trees (20+ inches in diameter): 6-8 weeks or longer
Factors Affecting Uptake Speed
- Tree Health – Healthy trees with active sap flow absorb the insecticide more quickly.
- Soil Moisture – Proper watering before and after injection improves uptake. Drought-stressed trees absorb more slowly.
- Temperature & Season – Uptake is fastest when the tree is actively growing (spring to early summer). Cold weather slows absorption.
- Tree Species – Some species, like ash and birch, transport TREE-äge faster than dense hardwoods like oak.
When Does TREE-äge Start Working?
- Sap-feeding pests (e.g., aphids, leafhoppers): 4-6 weeks after injection.
- Wood-boring insects (e.g., Emerald Ash Borer, Bronze Birch Borer): 6-8 weeks for full systemic protection.
Anytime that the tree has leaves, typically about May through September.
The duration of this treatment typically lasts between 1 to 3 years, depending on the specific insect being treated. If the insect poses a fatal threat to your tree, consider scheduling another treatment after 2 years. However, if the insect only weakens the tree without causing death, a treatment after 3 years may suffice. For cases involving the Emerald Ash Borer, we may transition to annual root injections following the initial Tree-Age treatment.
We are unsure about treating trees with a diameter at breast height of less than 2 inches. While we have had good results with smaller trees in the past, we cannot guarantee that they will survive the treatment. Therefore, it is not recommended to treat trees below this size, as we cannot ensure their safety during the process.
Once injected, TREE-äge is absorbed into the tree’s vascular system, providing long-lasting protection by targeting insects as they feed on the tree’s tissues. It effectively kills larvae inside the tree and prevents adult infestations.
Yes! TREE-äge is most effective as a preventative treatment. If a tree is already infested, treatment may still help, but early application ensures the best protection.
Yes, and No! TREE-äge can be used reactively, but it is most effective as a preventative treatment. When applied to a tree that is already infested, TREE-äge can help stop further damage by killing active larvae and preventing new infestations, but it cannot reverse existing structural damage caused by pests like Emerald Ash Borer (EAB), Bronze Birch Borer, or Pine Bark Beetles.
Limitations of Reactive Treatment
- TREE-äge cannot repair structural damage or regrow lost canopy.
- If more than 50% of the canopy is lost, survival chances decrease significantly.
- Severely infested trees may still decline, even after treatment.
- For Reactive Treatment of Emerald Ash Borer – Typically if an ash tree is showing signs of damage it is too late to save the tree.