How to Get Rid of Peach Tree Borers Before They Destroy Your Fruit Trees

If you’ve recently planted a stone fruit tree in your backyard, there’s one pest you’ll want to watch for: the peach tree borer. And gardeners who’ve been growing these trees for years are often already familiar with this insect—but that doesn’t mean they’ve figured out how to control it.

The peach tree borer (Synanthedon exitiosa) is a clearwing moth that feeds on stone fruit trees, such as peaches, nectarines, plums, and apricots. They attack the lower trunk, crown, roots, and main structure of the tree. Peach tree borers feed beneath the bark, making them difficult to detect until serious damage has occurred. 

To protect your garden and ensure an abundant harvest, we consulted with pest experts and arborists, who shared their tips for identifying peach borer damage and effectively controlling these insects.

How to Identify Peach Tree Borers

Adult peach tree borers resemble stinging wasps, an evolutionary trick designed to scare away predators. Adult females are typically bigger than males. "The adult females have a 1.5-inch wingspan, with dark metallic blue bodies, dark opaque front wings, and a very distinct, bright orange band around their midsection," says Timothy Wong, technical director of MMPC. "The males are noticeably smaller and much more delicate, with completely clear wings and three to four narrow yellow or white stripes across their abdomen."

While the adults are easy to identify, the larvae that do the destruction are trickier to see. "The larvae are cream-colored and live beneath the bark, which is where the damage occurs," says John Rogalsky, certified arborist and founder of Rick’s Certified Arborists. "Most people never see the insect, only the evidence it leaves behind."

The Lifecycle of the Peach Tree Borer 

The peach tree borer follows a one-year lifecycle. The adult clearwing moths emerge in summer and lay hundreds of eggs near the base of stone fruit trees. "The larvae hatching from eggs immediately bore into the tree bark. A single female can lay up to 500 eggs, so multiple larvae can infest the same tree," says Grzegorz Krawczyk, extension tree fruit entomologist for Penn State University. The larvae overwinter inside the tree’s wood. Once spring arrives, they briefly resume feeding before pupating and eventually emerging as adult moths in summer to mate and repeat the cycle, says Wong. 

Symptoms of a Peach Tree Borer Infestation 

To identify a peach tree borer infestation, inspect the bottom of the tree trunk. "The most definitive warning sign is gummosis, a mass of thick, jelly-like sap mixed with reddish-brown, sawdust-like excrement (frass) oozing near the soil line," says Wong. "Beneath this gooey sap, you may find cracked bark, shallow feeding tunnels, or the cream-colored larvae themselves."

As the infestation worsens, you may see wilting leaves, premature leaf drop, and canopy dieback. "If the canopy is already thinning without a clear reason, the problem has likely been active for some time," says Rogalsky, adding that early detection is essential to getting infestations under control.  

How severe the damage is depends largely on the tree’s age. "If a young tree is infested, it can die directly from multiple larvae feeding, or indirectly from being weakened by larval feeding and dying from other weather-related factors, such as wind, frost, or drought," says Krawczyk. "Older trees, if attacked later, can withstand more larvae, although the feeding also creates entry points for diseases that can kill the tree."

Related Stories

How Often to Water a Peach Tree to Maximize Fruit and Flavor

7 Companion Plants That Supercharge Peach Trees and Keep Pests Away

How to Get Rid of Peach Tree Borers

Peach tree borer infestations can be difficult to manage, but there are ways to get rid of these insects without using synthetic pesticides. Early intervention is key, as their presence becomes more challenging to control once larvae are established. 

• Mechanical removal: The larvae can be mechanically removed as long as they are found early in their development. "This method requires continuous observation of the tree trunks and manual removal of very small larvae throughout the growing season," says Krawczyk.
• Natural pyrethrum: Krawczyk notes that organically approved insecticides, such as natural pyrethrum, can also help. Natural pyrethrum. a botanical insecticide derived from the flower heads of Dalmatian daisies, paralyzes insects. However, due to its short residual properties, Krawczyk says sprays must be reapplied weekly during the moth's flight.
• Worming: This is a viable method for small-scale infestations. “In autumn, after larvae have hatched but before they burrow too deeply, you carefully excavate the soil away from the tree base. Upon finding the gummy frass, use a flexible wire or pocketknife to probe the tunnels and manually impale the larvae,” says Wong. “It requires precision to avoid cutting healthy bark, which can cause more damage than the borer.”
• Entomopathogenic nematodes: This is a type of biological control. "In late summer or autumn, beneficial microscopic roundworms (like Steinernema carpocapsae) can be applied to the lower trunk and soil," says Wong. "The nematodes hunt and kill the larvae naturally."

How to Prevent Peach Tree Borers From Returning

The most effective way to keep peach tree borers away from your garden is to prioritize tree health. "Trees dealing with drought, poor planting, mechanical injury, or disease are more vulnerable," says Rogalsky. "Healthy trees can still be attacked, but stressed trees decline faster."

To maintain tree health, Rogalsky recommends providing consistent moisture, especially during summer drought, and avoiding over-pruning during periods of stress. "Keep the base of the tree properly exposed by clearing excess soil and maintaining the root flare," he says. "Ongoing monitoring is critical, as most problems begin when attention drops off."

Keeping the area around the tree weed-free and surrounding vegetation low is also essential to preventing peach tree borers. "Removing weeds and heavy mulch exposes the soil to direct sunlight and wind, which causes heat and desiccation that severely reduces egg survival," Wong says. 

What to Do If Your Tree Dies

If you lose a tree to a borer infestation, there are important steps you must take before growing another tree in its place. "The old tree stump and roots must be completely dug up and destroyed before replanting," says Wong. "When a tree dies from borers, there is a high probability that larvae are still hibernating deep inside the root crown. If they are not completely removed and you plant a new sapling next to it, those borer larvae will wake up in the spring, emerge as adult moths, and immediately lay eggs on the new tree."

When buying a new tree, Rogalsky says to source high-quality nursery stock from a trusted supplier and consider pest- and disease-resistant varieties. "Before replanting, address the conditions that made the tree vulnerable in the first place, including soil, drainage, planting depth, and overall stress," he says. Plant the tree in fall when conditions are more favorable, as spring and summer can be stressful periods for trees.