About EAB

Emerald Ash Borer, also called EAB, is an invasive beetle native to Asia that was first identified in North American in 2002. It attacks ash trees by feeding on the water and nutrient tissues underneath the bark. Initial warning signs include woodpecker activity, gradual dying of branches, and thinning of the canopy.

Since 2002, EAB have killed more than 30 million ash trees in southeastern Michigan alone, with tens of millions more lost in Ohio and Indiana. The insect was identified in northern Illinois and Maryland in 2006, and western Pennsylvania and West Virginia in 2007.

Extensive containment efforts have not been successful in stopping the spread of this destructive pest. "Early on, some tree-care experts said EAB could only be controlled by cutting down the trees eliminating their habitat. But this is simply not true. Cutting down the has not stopped the spread and many homeowners cut down trees which could have been saved.

Over the Last seven years a direct inject applications have saved thousands of ash trees, providing proven control of EAB preventively and curatively, even in heavily infested areas. Numerous arborists have documented their success. Here are two examples:

Thousands of ash thrive amidst EAB infestation

"Last year I treated around 2000 ash trees and only lost three. Since 2002, in Michigan and Ohio, I've treated thousands and thousands of ash with a direct inject application. Nearly all of these trees are thriving, often while every untreated ash nearby has died. I am totally confident that with the direct-inject application system is the most effective, efficient treatment available.

Wayne White (Board Certified Master Arborist Emerald Tree Care, LLC)  

Case study:  99% survival rate

in Grosse Pointe Farms, Michigan, an island of ash thrives amid a sea of dead trees. Since 2002, Shock Brothers Tree Service has been treating ash trees in the city with Direct-Inject application. In that time, only 3 of 640 ash trees being treated have been lost to EAB

How often should you treat your trees?

When treating preventatively, you can treat every two years. In areas of heavy infestation, or if your tree is already infested, annual treatments are recommended.

What will happen if you treat your trees but the city/neighbor is not treating the trees nearby?

Tree studies and field use since 2001 have shown that tree that are treated can thrive even in areas with heavy insect pressure evidenced by swarming of EAB adults within 50 feet of trees. In Fact, Groups of treated trees survive in areas surrounded by Hundreds of trees which have died from EAB infestations.  

Top Left Photo: Typical decline symptoms caused by the Emerald Ash Borer include upper branch thinning, yellowing and decline, and epicormic shoots emerging from the trunk

Top Right Photo: Adult EAB emergence holes are D-shaped. Bark has been stripped, and larger jagged holes created, by woodpeckers in search of EAB larvae as food.

 Middle Left Photo: Adult EAB measure about one-eighth by one-half inches.

Bottom Right Photo: The destructive phase of EAB attack is performed by larvae that destroy cambial tissues in a serpentine pattern.

Bottom Left Photo: Larvae are segmented and measure over one-inch when mature.

Frequently Asked Questions

Q: Where did the emerald ash borer come from?

A: The natural range of Agrilus planipennis, or the emerald ash borer, is eastern Russia, northern China, Japan, and Korea. Before June of 2002, it had never been found in North America.

Q: How did it get here?

A: We don't know for sure, but it most likely came in ash wood used for stabilizing cargo in ships or for packing or crating heavy consumer products.

Q:What types of trees does the emerald she borer attack?

A: In North America, it has only been found in ash  trees. Trees in woodlots as well as landscaped areas are affected. Larval galleries have been found in trees or branches measuring as little as 1-inch in diameter. All species of North American ash appear to be susceptible.

Q:Where has it been found?

A: IN 2002, EBA was thought to occur in six counties in southeastern Michigan: Livingston, Macomb, Monroe, Oakland, Washtenaw and Wayne, and in Essex County Ontario. Our Ability to detect and find EAB has substantially improved since then, however, and we now realize that a much greater area was infested than what was initially thought. Now there are only three counties in Michigan where EAB has not been detected. It has also been found in Illinois, Indiana, Kentucky, Maryland, Minnesota, Missouri, New York, Ohio, Pennsylvania, Virginia, West Virginia, Wisconsin, Ontario and Quebec, making EAB an international pest problem. Most of these infestations are not new (i.e., EAB has not spread this far in the past 5 years). We are simply getting better at finding infestations as survey methods improve. However, it is important to watch for signs and symptoms of EAB in non-quarantine areas where the beetle may have been accidentally transported in ash firewood.

Q:What happens to infested ash trees?

A: The canopy of infested trees begins to thin above infested portions of the trunk and major branches because the borer destroys the water and nutrient conducting tissues under the bark. Heavily infested trees exhibit canopy die-back usually starting at the top of the tree. One-third to one-half of the branches may die in one year. Most of the canopy will be dead within two years of when symptoms are first observed. Sometimes ash trees punch out sprouts from the trunk after the upper portions of the tree dies. Although difficult to see, the adult beetles leave a "D" shaped exit hole in the bark, roughly 1/8 inch in diameter, when they emerge in June.

Q: What do emerald ash borers look like?

A: The adult beetle is dark metallic green in color, 1/2 inch long and 1/8 wide.

Q:What is the life cycle of this borer?

A: Recent research shows that the beetle can have one or two year life cycle. Adults begin emerging in mid to late May with peak emergence in late June. Females usually begin laying eggs about two weeks after emergence. Eggs hatch in 1-2 weeks, and the tiny larvae bore through the bark and into the cambium - the area between the bark and wood where nutrient levels are high. The larvae feed under the bark for several weeks, usually from late July or early August through October. The larvae typically pass through four stages, eventually re aching a size of roughly 1 to 1.25 inches long. Most EAB larvae overwinter in a small chamber in the outer bark or in the outer inch of wood. Pupation occurs in spring and the new generation of adults will emerge in May or early June, to begin the cycle again.

Q:How is this pest spread?

A: We know EAB adults can fly at least 1/2 mile from the tree where they emerge. Many infestations, however, were started when people moved infested ash nursery trees, logs, or firewood into uninfected areas. Shipments of ash nursery trees and ash logs with bark are now regulated, and transporting firewood outside of the quarantined areas is illegal, but transport of infested firewood remains a problem. PLEASE -  do not move any ash firewood or logs outside of the quarantined area.

Q: How long gas the emerald ash borer been in Michigan?

A: The beetle was first found in Ohio Feb. 28, 2003 in Whitehouse, near Toledo (Lucas County). Evidence suggests that emerald ash borer had been in the United States for at least 10 years before it was detected.

Q: Does it only attack dying or stressed trees?

A: Healthy ash trees are also susceptible, although beetles may prefer to lay eggs or feed on stressed trees. When EBA populations are high, small trees may die within 1-2 years of becoming infested and large trees can be killed in 3-4 years.

Q: What is being done on a statewide basis about this new pest?

A: Many agencies and universities are working together to educate citizens about identification of ash trees and EAB and options for protecting valuable shade trees. State and federal agencies have programs in place to help restore the urban forest in cities that sustained heavy EBA damage. Research is underway to learn more about the biology of EAB, its rate of spread, methods for EBA detection, predators and other natural enemies that may attack EAB, and how insecticides can be used to protect trees infested areas.

Q: How big a problem is EAB? 

A: EAB is becoming an international problem, with infestations in Canada as well as Michigan, Ohio, Indiana, Illinois, Pennsylvania, Missouri, Wisconsin, Maryland, West Virginia, and Virginia. The scope of this problem could reach the billions of dollars nationwide if not dealt with. State and federal agencies have made this problem a priority. Homeowners can also help by carefully monitoring their ash trees for signs and symptoms of EAB throughout the year.

Q: Who do I call to get more information on the Emerald Ash Borer or to report and infested tree?

A: Contact your county Extension office or the nearest Department of Agriculture office. You may also contact the USDA Emerald Ash Borer hot-line toll-free at 1-866-322-4512 or your local tree service.