MANAGE FORESTS & LAND
  • FOREST HEALTH: EMERALD ASH BORER

     

    The emerald ash borer (Agrilus planipennis) is a destructive, non‐native, wood‐boring pest of ash trees (Fraxinus spp.). Native to Asia, the emerald ash borer beetle (EAB) was unknown in North America until its discovery in southeast Michigan in 2002. Since then, the invasive pest has spread to 35 states including Texas, where it was first detected in Harrison County in Northeast Texas. EAB is responsible for killing millions of ash trees across much of the country. Ash trees are widespread in the United States and all 16 native ash species are susceptible to attack. Ash trees with low population densities of EAB often have few or no external symptoms of infestation. Symptoms of an infestation may include any or all of the following: dead branches near the top of a tree, leafy shoots sprouting from the trunk, bark splits exposing larval galleries, extensive woodpecker activity, and D‐shaped exit holes (see photo gallery for images). EAB is a significant threat to urban, suburban and rural forests as it kills both stressed and healthy ash trees. EAB is very aggressive, and ash trees may die within two or three years after they become infested.


    Emerald Ash Borer Fact Sheet

     

    Current Situation

    EAB was first detected in Texas in April 2016 when four adult EAB beetles were caught and confirmed in a monitoring trap in Harrison County just south of Karnack. Texas A&M Forest Service began monitoring for the pest in 2012 by strategically deploying detection traps each spring. The traps are monitored throughout the spring and summer months during peak EAB emergence and movement.

    As of July 2023, EAB has been detected in 13 additional counties since the original Harrison County detection was made in 2016. Additional positive confirmations have been made in Bowie, Camp, Cass, Cooke, Dallas, Denton, Marion, Morris, Parker, Rusk, Tarrant, Titus and Wise counties as well. Undoubtedly EAB will continue to move in and around these areas and it is possible that new detections will be made in other counties. Texas A&M Forest Service continues to monitor the movement of EAB through its trapping program and remains vigilant in evaluating potential EAB sightings across the state. 


     + Identifying ash trees and symptoms of EAB

    Identifying ash trees

     Trees of Texas tree identification website can help you learn to observe a tree's leaves, structures and shapes. With these characteristics, you can identify your tree. And by exploring the links, you can understand more about how trees grow and where.

    To help you identify your ash tree Ash tree identification guide by Arkansas Cooperative Extension Service

    A few examples of ash trees found in Texas include: Arizona, Carolina, Green, Mexican, Texas, Water and White

       

    If you have an ash tree in your yard, you have options and decisions to make


        Plan for treatment, removal and replacement of ash trees

        Diversify your tree canopy by planting trees not susceptible to emerald ash borer (non-ash trees)

        To learn more about EAB management           

    •  Refer questions to your local Texas A&M Forest Service office
    •  Certified arborists can help you manage your trees
    •  Visit the Emerald Ash Borer website

     

     How can I tell if my ash tree is showing symptoms?

    Ash trees with low population densities of EAB often have few or no external symptoms of infestation.

    Symptoms of an infestation may include any or all of the following:

    •     dead branches near the top of a tree
    •     leafy shoots sprouting from the trunk
    •     bark splits exposing larval galleries
    •     extensive woodpecker activity
    •     D‐shaped exit holes
     + How EAB spreads and kills ash trees

    Where did EAB come from and how does it spread?

    EAB was initially found in the United States in Detroit, Michigan in 2002 and has spread throughout much of the country since. The spread occurs, at least in part, through the movement of ash tree wood from infested areas to previously non-infested areas.

     

    How does EAB kill an ash tree?

    Because the EAB isn’t native to the U.S., our ash trees don’t have any defenses against this invasive insect and once the tree is infested it will die. Typically, the emerald ash borer beetles can kill an ash tree within two to three years of the initial infestation.

    The emerald ash borer weakens trees in the winter and kills them in the summer. Adults are dark green, one-half inch in length and one-eighth inch wide. They fly between the months of April and September, depending on the climate of the area. In Texas, most EAB adults would fly in May and June.

    Adult EAB lay larvae in the bark of ash trees in the late summer. They burrow into the bark and are sheltered by it during the winter months. The larvae feed under the bark (in the phloem and cambium) disrupting the flow of nutrients within the tree, potentially damaging the transport of water to the leaves of the tree.Through feeding on the ash tree, the larvae impair the tree’s ability to transport water and nutrients.

    When the beetles emerge as adults, they leave D-shaped holes in the bark about one-eighth inch wide.

     + What you can do and where to find help

    EAB management - what can I do?

    The damage to the ash population will be economically and ecologically devastating. It has the potential to wipe out the whole species, which could seriously affect rural and urban ecosystems.

    And the cost of removing dead or dying trees can be straining on budgets. Local communities and homeowners may pay to either attempt to prevent infestation or to remove infested trees from their properties.

     

    TAK EAB         

     

    Listen to and share the Trees Are Key to EAB podcast learn how to spot their damage, identify the culprit and what you can do to help.

     TAK EAB soundcloud


    Saving a tree


    If you have ash trees on your property, you have some decisions to make. The first choice is whether or not the tree is important enough to save. If it’s a tree that provides shade to your sun-porch or if it was planted in memory of a loved one, the answer may be ‘yes’. If you determine the tree to be insignificant, it can be turned into mulch or used for firewood. Be advised, though, EAB can survive for up to two years after a tree is cut down. So if you chop down an infested tree and move it to your woodpile, you may be moving EAB closer to other, still-healthy trees. (Five Things You Should Know About The Emerald Ash Borer)

     

    If you decide the tree is worth saving, you have options.

    Emerald Ash Borer Information Network: Information for Homeowners

    Integrated Pest Management Center: Insecticide Options for Protecting Ash Trees from Emerald Ash Borer

     

    Preventing EAB spread

    Don’t Move Firewood! Firewood is a very likely transportation method for the emerald ash borer. The beetle is also known to travel in unprocessed ash logs, ash nursery stock and other ash commodities.

    An EAB quarantine prohibits the movement of firewood, ash nursery stock, ash timber and other material that can spread EAB. It is important to know where the emerald ash borer quarantines are if you are traveling between infested states or between counties that are known to be infested.

     

    Authorities are asking people follow these simple rules: 

    • Leave firewood at home. Don’t transport firewood, even within the state.
    • Use firewood from local sources near where you’re going to burn it, or purchase firewood that is certified to be free of pests (it will say so on the label included with the packaging).
    • If you have moved firewood, burn all of it before leaving your campsite.
    • Learn more at Don't Move Firewood


    To report any symptomatic ash trees, please contact your local TFS office or call the EAB hotline (866) 322-4512

    Emerald ash borer has been detected in over half the states in the United States. There is a wealth of knowledge and information you can explore.   

     

    Texas A&M AgriLife Extension Service (TAES)

    Emerald ash borer information sheet

    Texas Department of Agriculture (TDA)

    Texas Parks & Wildlife Department (TPWD)

    USDA Animal & Plant Health Inspection Service, Plant Protection & Quarantine (APHIS PPQ)

    USDA Forest Service, Forest Health Protection (FHP)

    Level 1 Tree Risk Assessment mobile app available through app stores

    Urban Tree Canopy of selected Texas communities

    i-Tree Tools for Assessing & Managing the Community Forest

    International Society of Arboriculture

    Guide for Plant Appraisal (Council of Tree and Landscape Appraisers)

    Find a Certified Arborist

    Emerald Ash Borer Information Network

    Emerald Ash Borer Cost Calculator

     + How to manage EAB

    Slow the spread

    EAB, like many pests and diseases, can spread long distances in wood. 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 create satellite populations. The Texas Department of Agriculture regulates the movement of potentially infested products from areas of known EAB outbreaks

       

    Tree removal

    Removing ash trees that are in poor condition or that are infested with EAB can help to slow the spread of the insect. Infested wood must be disposed of properly by chipping as insects can still emerge and travel to other trees, even after a tree has died and been cut down.

       

    Insecticide treatment

    Several commercially available products are registered for treatment of EAB. Trees can be treated with soil injections or drenches, trunk injections, or trunk sprays. 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.

       

    Biological control

    The Operation Biocontrol Program being conducted by USDA APHIS has successfully released parasitoids across the eastern United States. In many regions, biological control agents have been recovered and show promising results as the suppress EAB populations to low densities, allowing surviving trees to recover. Unfortunately, as of 2022, no parasitoids have successfully been released and recovered in the southern United States.

       

    Planting diversity

    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. A general guideline to follow is known as the 10-20-30 rule. This simple rule of thumb suggests that a tree population should include no more than 10% of any one species, 20% of any one genus, or 30% of any one family. Having a greater diversity of trees reduces the likelihood that they will be severely affected by an outbreak of any single insect pest or disease pathogen.

     + Preparing Texas communities: EAB and the urban forest

    Community EAB Preparedness Plan

    Texas A&M Forest Service can help communities develop, communicate and implement an EAB preparedness plan.

    The EAB preparedness plan will not necessarily prevent EAB or the loss of community ash trees, but instead give communities information and decision-making tools, minimizing the severity of the impact from the invasive insect.

     

    Guide for Texas Communities
    Community Forest Planning: Emerald Ash Borer
    State Summary of Potential EAB Impacts 

     

    Is there a silver lining?

    As a potentially positive outcome, the arrival of EAB avails communities the chance to diversify the urban forest tree population. Diversity of species can contribute to the health and resiliency of the forest.


    For information and guidance tree planting visit the Texas Tree Planting Guide

     

     

     What effects would losing all our ash trees have on our community?

     

    Losing and removing all the community ash trees without a mitigation or replacement plan could cause a/an

    •     permanent loss from urban forest that will take years, or generation to replace
    •     increased storm water runoff and water consumption
    •     enhanced heat island and greater energy costs
    •     decrease in property value and neighborhood character



             

     + Appreciating our ash trees

    Where are the ash trees? And how many are there?

    Ash trees are widespread in the United States and all 16 native ash species are susceptible to EAB attack.

     

     There are seven species of ash trees in Texas: Green, White, Carolina, Texas, Water, Mexican and Arizona Ash.

     

     Ash trees can make up a large population of urban forests. In Austin, Texas, for example, ash makes up 4.4% of the urban forest – that’s over a million trees.

     

     Ash trees make up less than 5% of rural Texas forestlands.

    Why are ash trees important?


    Ash trees are important to our environment and our economy. They help fill in the forest canopy and provide shade for the forest floor. They help keep our ecosystems diverse and stable.

    They provide shade—cooling our streets and homes. They help keep our air clean and our water pure.
    They help maintain our soil and manage storm water runoff. They also beautify and add value to the places we live, work and play.

    Ash trees are also important to us because of the products they provide.

     

    The wood of the white ash has unique qualities. It is pliable and strong, but light in weight. Many products are made from the wood of the white ash, including baseball bats, hockey sticks, guitars, boat oars, flooring and furniture. White ash also provides food for some wildlife—such as cardinals, finches and wood ducks.


    The wood of the black ash is not as strong as white ash, but has a grain look that is used for furniture. The wood of a young black ash can be split and used for cabinet making.

     + Frequently asked questions
    • Texas A&M Forest Service is working with U.S. Department of Agriculture APHIS and the Texas Department of Agriculture to continually assess the immediate area of the recent beetle capture for affected ash trees. Since the initial detection, the state agency has deployed additional traps in the immediate area to bolster the detection effort.

      About the traps
      The Texas Department of Agriculture and APHIS lead the national EAB detection program for Texas.  Purple box traps are placed in trees to determine if EAB is in the area. The traps are coated with an adhesive that captures insects when they land. 

      The color is attractive to EAB and is relatively easy for people to spot among the foliage.  

      Once EAB is detected in an area, TDA, the state’s regulatory agency, works with Texas A&M Forest Service, APHIS, Texas Forestry Association, forest industry, county and municipal leaders, and landowners to determine and establish a quarantine if needed. A quarantine, if set, may restrict movement of certain forest products and tree debris/waste outside of the quarantine area. Currently, quarantines have been established for Harrison, Cass, Marion, Tarrant, Bowie, and Denton Counties. The assessment and implementation process typically takes 60-90 days and is submitted to the public for comment prior to being implemented.

      For more information about EAB quarantines administered by TDA and APHIS, visit: 

      https://www.texasagriculture.gov/RegulatoryPrograms/PlantQuality/PestandDiseaseAlerts/EmeraldAshBorer.aspx

    • In preparation for the arrival of EAB to the state, Texas A&M Forest Service helped develop a multi-partner, state EAB response plan.

      The EAB response plan includes establishing each involved agency’s responsibilities, removing ash tree as a preemptive measure, selecting ash tree treatments and planting tree species not susceptible to EAB.

      Texas A&M Forest Service also is helping communities to develop, communicate and implement local EAB preparedness plans.

      These plans guide communities

      • in developing ash tree inventories
      • and planning for treatment, removal, disposal and replanting of trees

     

    • Hotline to Report: 1-866-322-451
  • RELATED INFORMATION