EAB Key: How do Exotic Invasive Species Change Ecosystems?

  • EAB Key: How do exotic invasive species change ecosystems?
    Purchase access to 3D stereolithography (.STL) models and accompanying lesson plans to print as many EAB Keys as you like!

    Model Price: $1.49

    Note: this lesson only for south-eastern Canada and north-eastern USA

    A video showing the EAB Key in use is now up on our YouTube channel. Check out how easy it is survey for trees affected by the emerald ash borer.


    Hits the standard: HS-LS2-2, HS-LS2-7
    HS-LS2-2: Use mathematical representations to support and revise
    explanations based on evidence about factors affecting biodiversity and populations in ecosystems of different scales.
    HS-LS2-7: Design, evaluate, and refine a solution for reducing the impacts of human activities on the environment and biodiversity.

    Lesson Brief:
    When humans move exotic species to new ecosystems what is the potential impact? Students will survey trees to estimate the proportion that are being killed by an exotic invasive beetle, the emerald ash borer. The 3D printed EAB Key will allow students to identify emerald ash borer exit holes without any insect or tree identification skills.

    The emerald ash borer, Agrilus planipennis, is a jewel beetle from Asia. North America has over 100 native species in this genus of jewel beetles, but the emerald ash borer was introduced by accident around the turn of the century near Detroit, Michigan. The immature stages or larvae live under the bark of ash trees. The galleries they carve through the living tissue under the bark girdle the tree, killing it. Most of the adults will fly much less than a kilometer (>1/2 mile) during their lifetime. However, the beetle has been spread rapidly since its introduction by humans moving firewood and nursery trees that were infested with the larvae.

    Additional information and images available at: https://wiki.bugwood.org/Agrilus_planipennis


    1. Use a 3D printer to make copies of the EAB Key for each team of students. Glue the top and bottom halves together with the knobs on the side aligned.
    2. Give each team a copy of the tree tally sheet with columns marked “Tree #” and “EAB?”.
    3. Define the tally area. If a forested area is available, select a random direction and have three
      students walk parallel with their arms outstretched and fingers just touching. All trees that they touch will be included in the tally until 50 trees have been checked. If doing an urban tally, survey the first 100 trees that are large enough that you cannot encircle the trunk with thumbs and forefingers touching. Each team of students will survey 100 trees.
    4. For each tree in the tally, write down the location and type (if known). Examine the trunk for any small holes. If any D-shaped holes are found, try to insert the EAB KeyTM. If the key fits snugly in the hole, put a check in the “EAB?” column, otherwise leave this column blank. This works because other beetles that leave a D-shaped exit hole in eastern North America are either slightly smaller than the emerald ash borer, or much larger.

    Analysis & Leading Questions:

    1. What proportion of the trees were killed by the emerald ash borer?
    2. How would this tree mortality scale to the entire forest or city?
    3. How would you estimate the economic cost of this damage?
    4. How would you estimate the ecological damage from this beetle?
    5. How will biodiversity be impacted by the introduction and rapid expansion of this beetle?

  • The "EAB Key" allows you to identify the exit holes of the exotic invasive Emerald Ash Borer in trees. You can do this in seconds with no knowledge of tree or insect identification.

  • A video showing the EAB Key in use is now up on our YouTube channel. Check out how easy it is survey for trees affected by the emerald ash borer.


    This works because there are no other species of wood-boring beetles in north-eastern USA and south-eastern Canada with precisely the same size and shape of exit wound. If the key fits snugly, it was EAB.

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