Tree Borer Treatments by SavATree Insects & Diseases Tree borers are destructive insects that tunnel into bark and wood, causing serious damage to landscape trees. While some borer species like emerald ash borers have gained recognition in certain regions, many other varieties pose equally serious threats that often go undetected. Bronze birch borers and Asian longhorned beetles are just two examples of these invasive insects. Without treatment, they lead to branch dieback, weakened structure, and can eventually kill your tree. SavATree's targeted treatments can effectively manage tree borer populations, helping protect your valuable landscape from infestation. Signs of a Tree Borer Infestation Detecting a borer infestation early is crucial for preventing widespread damage. Common signs vary among varieties of tree borer, but often include: Entry/exit holes: Small, perfectly round or D-shaped holes in the bark depending on the species Sawdust-like material: Fine wood shavings (also known as “frass”) around the base of the tree Sap flow: Excessive sap oozing from trunk or branches where borers have entered Thinning canopy: Progressive dieback of leaves and branches in the upper canopy Bark splitting: Cracks and splits in the bark above infested areas Gallery patterns: Distinct tunnel patterns visible under loose bark or when bark is peeled back Woodpecker activity: Increased woodpecker feeding may indicate hidden borer larvae. Your Expert Tip: Borer damage worsens rapidly, so if you spot even one of these warning signs, be sure to act quickly. For best results, inspect high-risk trees (like birch, ash, or stressed oaks) monthly during peak borer activity from spring to early fall, or call your certified arborist for help. Common Types of Tree Borers Bronze Birch Borer The bronze birch borer primarily attacks birch trees, particularly those already stressed by environmental factors. These insects are small and feature a metallic bronze coloring. They begin their infestations in the upper canopy and work downward from there. Bronze birch borer infestations typically begin in European white birch and other non-native birch species before spreading to other trees. They work quickly and can kill susceptible trees within 2-3 years of initial infestation. Asian Longhorned Beetle The Asian longhorned beetle (ALB) is an invasive insect that poses a serious threat to numerous hardwood species, particularly maples, elms, willows, and horse chestnuts. They have long, black and white banded antennae longer than their bodies, create perfect round exit holes that are about ½ inch in diameter, and produce coarse sawdust-like frass at the base of trees they infect. Because of the severe threat they pose, Asian longhorned beetle infestations are federally regulated. In areas where the beetle is detected, tree removal and quarantine measures are required by law to help prevent further spread. If ALB is suspected, professional identification and coordination with local or federal authorities is critical. Two-lined Chestnut Borer This native borer primarily attacks oaks and chestnuts, especially those weakened by drought, disease, or other stressors. These slender beetles: Create winding, S-shaped galleries beneath the bark Produce D-shaped exit holes similar to but smaller than those of bronze birch borer Often attack in conjunction with other stressors like oak wilt or drought Can contribute to oak decline syndrome in susceptible trees Your Expert Arborist Tip: Pay close attention to oak trees that have experienced drought stress in the previous one to two years, as these trees are particularly vulnerable to two-lined chestnut borer attack. To protect valuable oaks, implement a deep watering schedule during dry periods and apply a two-to-four-inch layer of mulch extending to the drip line to conserve soil moisture. What Causes Tree Borer Infestations? Most borers are attracted to trees already weakened by environmental stressors. These insects are often introduced when: Trees experience drought stress, making them more vulnerable to attack Storm damage creates wounds that serve as borer entry points Infected firewood or nursery stock brings borers onto your property Natural spread occurs from neighboring infested trees Borer life cycles vary by species, but most emerge in spring or summer, then mate and lay eggs on or under tree bark. Once larvae hatch, they typically bore deeper into the wood, where they can remain for months or even years depending on the species. Trees maintained in good health through appropriate watering, mulching, and fertilization can often resist or recover from minor borer attacks. How Do Tree Borers Harm Your Trees? The wood-boring and extensive tunnel networks created by these insects can harm your trees in several ways. The most severe effects of tree borers on your trees include vascular system disruption, the creation of structural weakness, and causing overall stress to your tree that reduces its ability to withstand environmental pressures. The tunneling activity of borer larvae is particularly damaging as it directly impacts the tree's cambium layer and sapwood, which are essential for growth and vitality. As larvae feed and create tunnels, they essentially cut off the tree's internal plumbing system, preventing water and nutrients from flowing between the roots and leaves—similar to placing a tight band around the trunk, but hidden inside the tree where you can't see it. The aesthetic damage caused by borers is particularly concerning for specimen trees that often serve as focal points in landscape designs. This damage not only affects the beauty of your trees but can also compromise their structural integrity, sometimes requiring removal for safety. For these reasons, SavATree offers comprehensive insect management solutions that address tree borers and many other potential threats. How Are Other Tree Borers Different Than Emerald Ash Borers? EAB attacks healthy trees, while most borers target stressed ones. EAB spreads faster (often via firewood transport). Most borers have a life cycle less than one year long, but under certain circumstances EAB may live up to two years How to Identify Specific Tree Borers Bronze Birch Borer Adult beetles: Slender, bronze-colored beetles about 1/2 inch long Larvae: Cream-colored, flattened grubs with enlarged segment behind head Damage pattern: Begins in upper crown with progressive dieback moving downward Primary targets: White birch, river birch, and other birch species Asian Longhorned Beetle Adult beetles: Large (1-1.5 inches long) shiny black beetles with white spots Distinctive feature: Extremely long black and white banded antennae Damage signs: Large round exit holes, pitted egg-laying sites, coarse frass Primary targets: Maple, elm, willow, birch, horse chestnut, and other hardwoods Two-lined Chestnut Borer Adult beetles: Slender, black beetles (1/4-1/2 inch long) with two golden stripes Larvae: White, segmented grubs with flattened bodies Damage pattern: Winding galleries beneath bark, progressive crown dieback Primary targets: Oak and chestnut species, particularly stressed trees Regional Distribution of Tree Borers Borer species vary significantly by region across the United States: Northeast & Mid-Atlantic: Two-lined chestnut borer is common in oak-dominated forests and landscapes in this region. Midwest: Bronze birch borer is widespread here, particularly in urban landscapes where European white birch is common. Two-lined chestnut borer has become more problematic during recent drought cycles in this region. Southeast: Ambrosia beetles are particularly troublesome in this region, along with flatheaded appletree borer. Two-lined chestnut borer affects oaks throughout the region, especially following drought or hurricane damage. West Coast: Bronze birch borer is less common here, but the Pacific flatheaded borer affects many landscape trees. In California, the goldspotted oak borer has caused significant mortality in oak species. Rocky Mountain Region: Mountain pine beetle and other conifer borers dominate in this region, while bronze birch borer affects landscape birch trees in developed areas. Understanding your region's specific borer threats allows for more targeted preventive strategies. Your SavATree arborist will be familiar with local borer populations and can customize protection plans based on your location's specific risks. How Do Treatment Options Vary for Various Tree Borers Different tree borers require specialized treatment strategies. More borer management options include: Preventive soil treatments: Applied around the tree's root zone to protect against future infestations Trunk injections: Delivering targeted protection directly into the tree's vascular system Bark treatments: Timed applications to target adult borers before they lay eggs Canopy treatments: Used strategically when borers feed on foliage before boring into wood Strategic pruning and fertilization: removal of heavily infested branches combined with properly timed fertilization to boost tree vigor and natural defenses At SavATree, our certified arborists customize borer treatments based on tree species and health, borer type, life cycle state, and local conditions (with significant timing variations by region). Our available treatment options may include: Systemic soil treatments : Absorbed by roots to protect from the inside. Growth regulators : Promote root vigor over canopy growth in stressed trees. Root zone excavation services: Improve soil and root health (where available). SavATree specialty treatments: Like ArborKelp® and ArborHealth® to boost resilience. Treatment timing is critical, and post-treatment monitoring is equally important. We'll evaluate your tree’s response to treatment and adjust our approach as needed for optimal protection. Where to Find Tree Borer Treatment Near You If you're searching for "holes in tree trunk," "dying birch tree," or "oak branches dying," SavATree's ISA Certified Arborists can help. Our certified arborists develop customized treatment plans based on the specific borer affecting your trees, the extent of your infestation and tree damage, the health of affected trees, and additional environmental factors. Protecting your landscape from tree borers preserves the beauty, health, and value of your property. Contact us today to schedule a consultation with an expert arborist.