Emerald Ash Borer (EAB) confirmed in Johnson County, Kansas

by Dennis Patton, horticulture agent
Ash tree cambium layer damaged by Emerald Ash Borer larvae, found in Wyandotte County, KS summer 2013.

What we know — as of Spring 2014

  1. Adult EAB insects were found in a trap set by the United States Department of Agriculture (USDA) in Johnson County, Kans., in the area of I-435 and Holliday Drive, on July 5, 2013.

  2. Adult EAB insects have been also found in traps set by Kansas Department of Agriculture (KDA) in Wyandotte County, in the area of the first confirmed sighting in 2012.

  3. Johnson County is now under quarantine. Wyandotte County is also under quarantine.

Regulated items under quarantine include the following:
  • The emerald ash borer, (Agrilus planipennis [Coleoptera: Buprestidae]), in any living stage of development;
  • Firewood of all hardwood (non-coniferous) species;
  • Nursery stock of the genus Fraxinus (Ash);
  • Green lumber of the genus Fraxinus (Ash);
  • Other material living, dead, cut, or fallen, including logs, stumps, roots, branches, and composted and uncomposted chips of the genus Fraxinus (Ash);
  • Any other article, product, or means of conveyance that an inspector determines presents a risk of spreading emerald ash borer and notifies the person in possession of the article, product, or means of conveyance that it is subject to the restrictions of the regulations.

Points to consider when dealing with EAB

  1. Make sure the tree in question is an ash tree.
    1. How To Identify an Ash Tree
      1. If you are certain the tree is an ash (white or green), continue below.
      2. Uncertain of the tree species? Contact Extension at garden.help@jocogov.org for identification assistance, either by e-mailing photos of the tree or by bringing a sample to the office.
  2. Symptoms of EAB
    1. Twig dieback in the canopy or other branches of the tree.
    2. Sucker growth from the main trunk or around the base of the tree.
    3. Borer exit holes.  EAB borer holes are very difficult to see. These holes are usually not seen unless you are a trained spotter or the bark is peeled away. If you can easily see the holes it is unlikely to be EAB. There are many types of borers, including the very common native borers which have always been present.
      1. Borer hole size for native borers: about the diameter of a #2 school pencil and round in shape.
      2. Borer hole size for EAB: about the diameter of the lead in the pencil and “D”-shaped,  not round.
    4. Presence of adult insects. Adult EAB beetles are small, 1/8 to 1/4 inch and narrow, about the diameter of a flat toothpick, and metallic green. They are very difficult to see.
  3. Should you treat for EAB?
    1. Only highly valued trees in excellent condition should be considered for treatment.
    2. Trees with defects, such as decay, poor branching or in decline, should not be treated.
    3. Treatment should be considered a lifetime investment. Depending on the method of treatment, you must treat every year or two.
  4. What are the methods of treatments?
    1. Trunk spraying: Done every year and applied in the spring, prior to the emergence of the adults, from mid-May through early August. Recommended for commercial applicators only.
    2. Soil drench: A yearly application done by either homeowners or commercial applicators. The product is applied either in spring or fall depending on the product.
    3. Trunk injections: Applied every two years by a commercial applicator, normally done in early spring to early summer.  This is the preferred method of treatment supported by the most research.
    4. For complete information about control options visit: EAB Treatment Options.
  5. Can a homeowner apply the treatments themselves?
    1. There are products on the market for homeowners that are a soil drench.
    2. Must be applied yearly.
    3. Only recommended for trees under 20 inches in trunk diameter (measured at a height of 4 feet from the ground), some research suggests up to 16 inches in diameter.
    4. For complete information about control options visit: EAB Treatment Options
  6. Should we start treating our trees?
    1. Nothing needs to be done immediately.  For most highly-valued trees that are showing no signs of EAB (which, at this time, will be almost all ashes in Johnson County) no action is required in the summer of 2014.
      1. Do your research,
      2. Get quotes, and
      3. Make sound decisions based on science, not on impulse.
      4. If you wish to proactively treat to protect your tree from potential future EAB damage, you may consider treating in 2014. The likelihood of your tree being newly infected during the summer of 2014 is still low in Johnson County. The closer you live to a confirmed EAB find, the more inclined we are to recommend you begin to treat to prevent EAB.
    2. Treatment will be a personal decision based on your judgment of:
      1. the tree’s value,
      2. treatment cost and
      3. tree replacement cost.
    3. Remember only highly-valued trees in good or excellent condition should be considered for treatment.

Questions:  garden.help@jocogov.org