Adult emerald ash borers are colorful, but they are only about one-third to one-half inch long. (Howard Russell, Michigan State University, Bugwood.org)
In the fall of 2025, Mississippi received unwelcome news: the emerald ash borer (EAB), a destructive invasive beetle, was confirmed for the first time within the state’s borders, specifically in Issaquena County. This discovery marked a pivotal moment for gardeners, arborists, and landowners alike — and it’s a reminder that even well-established landscapes can be vulnerable to tiny invaders with a big impact.
What Is the Emerald Ash Borer?
The emerald ash borer (Agrilus planipennis) is a small, metallic green beetle native to Asia. Adults are strikingly colored but only about one-third to one-half inch long — roughly the size of a dime. It’s the larvae, not the adults, that cause immense harm. After eggs are laid in crevices on ash tree bark, the larvae tunnel just beneath the bark, feeding on the cambium and phloem — the tissues that transport water and nutrients. This feeding action girdles the tree, cutting off its lifelines and eventually causing death.
For decades, the emerald ash borer has devastated ash trees across North America. First detected in the United States near Detroit in 2002, EAB has since spread through at least 35 states and multiple Canadian provinces. Until recently, Mississippi had been one of the few eastern states spared from infestation — but the recent detection means the fight has now come to our home soil.
Why Gardeners Should Care
Ash trees (Fraxinus species) have long been valued in Mississippi landscapes. They provide dappled shade over patios and drives, serve as stately focal points in yards, and contribute to the local ecosystem by supporting birds and insects. While ash trees are not the most common tree in every yard, they are an important part of many natural and urban forests across the state.
The arrival of EAB is significant because once infested, untreated ash trees typically die within 3–5 years. Experience from other states suggests almost all untreated ash trees eventually succumb to the pest, with mortality often approaching 99%.
For gardeners, that means not just losing a beautiful tree but also facing the added expense and labor of removal and replacement. Large ash trees can become hazards when dead or dying, shedding heavy limbs or falling unexpectedly — a risk not to be taken lightly in a garden setting.
Recognizing the Signs
Early detection is essential. Here’s what keen observers should watch for:
Visual Symptoms
- Canopy thinning: the upper part of the tree looks sparse or dying back.
- Yellowing leaves: or wilting that isn’t explained by drought or disease.
- Epicormic shoots: shoots emerging from roots or the lower trunk, often with oversized leaves.
Physical Evidence
- D-shaped exit holes: adults chew their way out of the tree, leaving distinctive D-shaped holes in the bark.
- Serpentine galleries: if you peel back the bark, you might see winding, S-shaped tunnels carved by feeding larvae.
Wildlife Indicators
- Woodpecker activity: increased woodpecker feeding is often one of the first signs gardeners notice, as birds try to extract larvae from beneath the bark.
Spotting these signs early can make a real difference; trees with significant canopy loss are often too far gone to treat effectively.
What Gardeners Can Do
1. Monitor and Report
Now that EAB is confirmed in Mississippi, vigilance is crucial. Inspect your ash trees regularly and report suspected infestations to the Mississippi Forestry Commission or your local extension office. Early reporting helps forestry professionals map the spread and respond appropriately.
2. Prevent Human-Assisted Spread
Emerald ash borer can fly short distances on its own, but humans often accelerate spread by moving infested firewood, timber, or ash products. The simplest rule is: Buy and burn local firewood and never transport wood from other areas.
3. Treatment Options
If you want to protect high-value landscape ash trees, certain systemic insecticide treatments can be effective — but timing and method matter:
- Soil-applied treatments using products like imidacloprid or dinotefuran can be applied by homeowners but need yearly reapplication.
- Trunk injections with products such as emamectin benzoate (marketed as Tree-age) are more effective and can protect trees for 2–3 years at a time. These treatments are best applied by certified arborists.
Deciding whether to treat often depends on the tree’s health, size, and landscape value — as well as your budget. Treatments can be costly, and if a tree is already heavily infested, removal may be the better option.
A Call to Stewardship
For gardeners in Mississippi, the emerald ash borer presents both a challenge and an opportunity. It’s a stark reminder of the fragility of our green spaces — but also of the power of informed stewardship. By learning the signs, taking preventative steps, and working with extension and forestry professionals, we can slow the spread of EAB and preserve the ash trees that still stand.
In your garden journal this year, note the ash trees you have: their health, their location, and their importance to your landscape. Keep an eye out for early signs of trouble, and don’t hesitate to seek help. A little vigilance today could mean the difference between saving a treasured tree and watching it fade away.
For more information see Mississippi State University publication P3212 Protect Landscape Ash Trees from Emerald Ash Borers
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