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Texas Invasive Species Institute

Texas Invasive Species Institute

Emerald Ash Borer

Agrilus planipennis

Class: Insecta
Order: Coleoptera
Family: Buprestidae
Duration and Habit: Emerald Ash Borer targets Ash trees (Fraxinus sp.) in landscape, horticultural and forest settings.

Agrilus planipennis

Photographer:Unknown Affiliation: Pest and Diseases Image Library Source:www.bugwood.org Copyright:CC BY-NC 3.0


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 Eastern 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.

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.

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.


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.


Please report a possible sighting to the Sentinel Pest Network through Texasinvasives.org

Emerald Ash Borer was accidentally introduced into southeastern Michigan sometime in the 1990's in wood packing material imported from eastern Asia. Once in Michigan Agrilus planipennis spread quickly spread throughout the Northeastern United States. USDA and APHIS have performed annual surveys; along with other state entities TISI has helped survey in Texas for 2012 and 2013. In 2012, Agrilus planipennis was found Kansas, Connecticut and Massachusetts. In March 2013 it was found in New Hampshire, in North Carolina by June, found in Georgia by July, and found in Colorado by September 2013. The infestation in Colorado marks the western most occurrence of this insect in the United States; and Georgia marks the southern most. The Cooperative Agricultural Pest Survey (CAPS) results for 2014 have shown this beetle has now expanded into Arkansas (6 counties) and New Jersey. The counties infested with EAB in Arkansas are in southwestern Arkansas right along the Texas border. In February 2015, EAB was confirmed in Louisiana. All states with a confirmed presence of EAB are under quarantine run by USDA/APHIS and PPQ.

For a map of the distribution, survey and eradication efforts click here

On May 23, 2016 the presence of EAB was confirmed in Harrison County by the U.S. Forest Service and Texas A&M Forest Service.

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. This map shows the current affected counties.

INFESTED 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.

Native Origin


Current Location

AR, CT, CO, GA, IA, IL, IN, KS, KY, LA, MA, MD, MI, MN, MO, NC, NH, NJ, NY, OH, PA, TN, TX, VA, WI and WV

TEXAS 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.


Native Agrilus sp.


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. Systemic insecticides that list emamectin benzoate as the active ingredient are recommended in areas where EAB is present. These insecticide injections can protect a tree for 2-3 years and can be done either therapeutically or to prevent attacks of EAB. Contact a certified arborist (www.waa-isa.org/arborists/search.asp) 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 Eastern Ash Borer. Replace trees with a non-ash species suitable to your site. Trees larger than 10 inches diameter produce more Eastern Ash Borer and should be considered a priority for removal.


Wisconsin's Emerald Ash Borer Information Source. 2010. What does EAB Look Like> Accessed 18 Nov. 2010:http://www.emeraldashborer.wi.gov/article.jsp?topicid=15

USDA-APHIS. 2010. Plant Health: Emerald Ash Borer. Accessed 18 Nov. 2010: http://www.aphis.usda.gov/plant_health/plant_pest_info/emerald_ash_b/background.shtml.

Internet Sources







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