Agrilus planipennis Fairmaire, 1888 (Emerald Ash Borer )


David Cappaert,
Michigan State University




Class: Insecta

Order: Coleoptera

Family: Buprestidae


Adult Description: The Emerald Ash Borer (Agrilus planipennis) are uniformly bright metallic emerald green, with the elytra usually appearing somewhat duller and slightly darker green. The overall greenish coloration may also have variable amounts of brassy, coppery or reddish reflections. A few rare specimens of Emerald Ash Borer are entirely coppery-red, blue-green, or green with blue elytra. Length: 10.0-13.0 mm. Emerald Ash Borer is somewhat larger in size and more brightly metallic green than most other U.S. Agrilus species.

The dorsal surface of the abdomen is bright coppery-red. This may only be visible if the elytra and wings are raised. This is the only Agrilus species found in North America in which the dorsal surface of the abdomen bright metallic red. This may be the simplest diagnostic character for separating Emerald Ash Borer from all other Agrilus species in North America. The dorsum of the abdomen is normally black, green or blue on all other North American species of Agrilus.
If you think you have spotted an Emerald Ash Borer REPORT IT here

Larva Description: Emerald ash borer larvae are white and slightly flattened, with a pair of brown pincher-like appendages on the last abdominal segment. Their size varies as they feed under the bark of the ash tree's tissues. Full grown larvae average 1.5 inches in length. They wind back and forth as they feed, creating characteristic S-shaped patterns called galleries under the bark.

Host Plant: Ash trees (Fraxinus);
White fringetree (Chionanthus virginicus)

History: Emerald Ash Borer was accidentally introduced into southeastern Michigan sometime in the 1990's in wood packing material imported from eastern Asia.It was officially detected in Michigan in 2002.

Biology: Larvae will feed under the bark for one or two years (longer in healthy trees), and can survive in green wood, such as firewood, even if the tree is no longer standing.

Humans unknowingly contribute to the artificial spread of the Emerald Ash Borer. The movement of common ash tree products, such as firewood, nursery stock, green lumber, branches, logs, and chips, has been a primary means of advancing the beetle's spread.

Ecological Threat: Larvae feed in the phloem and outer sapwood of Ash trees producing galleries that eventually girdle and kill the tree. This invasive pest has had a devastating impact on communities that now face significant tree removal costs associated with dead or dying ash trees that pose a threat to public safety. Other repercussions include decreased property value, losses in the long-term supply of ash wood, decreased air quality, increased electricity use during hot weather, and negative impacts on Native American cultures that use ash wood for traditional crafts and ceremonies. In addition, there are other detrimental impacts on wildlife and natural ecosystems. States which become infested could lose billions of dollars in forest products and quarantines imposed by state and federal agencies and may have serious consequences for plant and wood products industries. Severe damage may also occur within the tourist industry with the loss of tree cover in campgrounds.

US Habitat: Emerald Ash Borer targets Ash trees (Fraxinus sp.) in landscape, horticultural and forest settings. Also known to attack white fringetrees (Chionanthus virginicus).


Native Origin: Asia

US States: (2024) AL, AR, CO, CT, DE, GA, IA, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, NC, NE, NH, NJ, NY, OH, OK, PA, RI, SC, SD, TN, TX, VA, VT, WI, WV

Also found in at least 5 Canadian provinces.

Texas: Discovered in a trap in NE Texas in 2016. Adults found in Bowie, Cass, and Marion Counties, infestations in Denton, Harrison and Tarrant Counties (June 2020). In 2022, the beetle was reported from Dallas County and Hood County the following year.
If you believe you have found an emerald ash borer, please report this species immediately.

AS OF JUNE 2024, EAB has been detected in 23 additional counties since the original Harrison County (2016) detection. The recent jump southward to Hood, Hill and McLennan Counties confirms that the EAB will continue to move around these areas and spread to others. Upon detection counties are Quarantined by the Texas Dept of Agriculture.
INFESTED & QUARANTINED COUNTIES: Bowie, Camp, Cass, Collin, Cooke, Dallas, Denton, Franklin, Grayson, Hill, Hood, Hopkins, Johnson, Marion, McLennan, Morris, Palo Pinto, Parker, Red River, Rusk, Tarrant, Titus and Wise Counties.

Resembles: Native Agrilus sp.
See description above for information on how to distinguish EAB from native species.

Management: Slow the spread: Since EAB lives within Ash trees, buying and using only local firewood can keep this insect from spreading to new locations. Movement of ash nursery trees and other wood products can potentially allow EAB to reach new areas and establish populations.

Insecticide: Treat with an insecticide only if the tree is apparently healthy or less than 40 percent of the crown has died, discolored, or has sparse foliage. Research has shown that trees with more than 40-50 percent crown dieback do not benefit from treatment. Treatment requires a long-term commitment. Contact a certified arborist ( to evaluate your treatment options.

Remove and Replace: This is an option for ash trees in all stages of health. Contact a certified arborist to remove trees from your yard and to appropriately process wood to prevent additional spread of Emerald Ash Borer. Replace trees with a non-ash species suitable to your site. Trees larger than 10 inches diameter produce more Emerald Ash Borer and should be considered a priority for removal.

When planting trees, either to replace those lost as a result of EAB or simply to add new trees to the landscape, planting a diverse array of species is one of the best ways to prevent significant losses in the future.

Text References

Wisconsin's Emerald Ash Borer Information Source. 2010. What does EAB Look Like> Accessed 18 Nov. 2010:

USDA-APHIS. 2010. Plant Health: Emerald Ash Borer. Accessed 18 Nov. 2010:

Data Source
U.S. Forest Service - Forest Health Protection
Texas A&M University Forest Service EAB site
EAB attacks white fringetrees
Texas A&M Forest Service EAB Page

Last Updated: 2024-06-05 by Ashley Morgan-Olvera, TISI