WHAT IS IT? An invasive beetle that was first found in Michigan in 2002. The metallic green adults feed on ash leaves in the spring before depositing their eggs on the
tree regardless of health status. The metallic menace has made it's presence known in 18 States within a decade.
SIGNS & SYMPTOMS: In the initial phase of infestation, the trees show thin or thinning crowns during the growing season. This may be followed by premature leaf drop
in summer or early fall. Woodpecker activity is heightened, as evidenced by bark peeling or 'flecking'. The birds are a barometer of borer infestation levels. As the internal
damage increases, the tree begins redirecting energy efforts to epicormic shoots from the trunk. Water sprouts may also begin growing off the main scaffold limbs. In the
heavier levels of infestation, the woodpecker injury becomes more pronounced, as borer emergence holes are widened. In large ash trees, the holes and flecking are
usually on the upper limbs of the crowns. With closer scrutiny, smaller D-shaped holes indicate successful emergence of the adult beetles. Vertical splits begin to manifest
on the trunk and limbs, which erupt from larval tunneling directly beneath the bark. As the split widens, the serpentine galleries of the immature stage are revealed.
WHAT CAN BE DONE? The first decision that you personally must make is whether or not you want your ash tree(s) in the future landscape setting. If you decide to
keep your tree, you should then perform cost analysis with and without your tree, http://extension.entm.purdue.edu/treecomputer/index.php The Coalition for Urban
Ash Tree Conservation issued their stance on the future of ash trees in the United States. They are of the opinion that ash trees can be saved, and that not all within EAB
range should be deemed removal candidates. They support the EPA's registration and endorsement of three specific systemic products for EAB control,
CONTROL OPTIONS: If the ash tree has at least 75% viable crown, and has a good overall form with no structural defects, treatment options can be evaluated. None
of the treatment options can be guaranteed. Trees with known EAB infestation levels may continue to decline, even after control treatments have been implemented. For
small trees (less than 8" dbh = diameter breast height 4.5'), a soil drench treatment can be performed. The soil drench is the lowest cost treatment, and it does not involve
wounding the tree (non-invasive). This option lasts for one growing season, so it requires annual applications. It can take 30-60 days for the product to move into the tree
with enough strength to become effective. The soil drench option should only be performed as a preventative treatment, and not for trees with EAB infestations. The
second option is best suited for medium sized trees that are less than 20" dbh. The trunk drench is a non-invasive delivery technique that is mid-range in effectiveness
and cost. It consists of spraying a systemic product on the trunk and scaffold limbs. This option is only performed in the spring, and it should be scheduled annually.
The third option is an invasive delivery technique that is best suited for large trees, although smaller trees can be treated. The trunk injection treatment (or
micro-infusion) involves directly injecting a systemic product in to the tree trunk. it can be performed in environmentally sensitive ares. The treatment last for 2 years, and
it provides the strongest protection. It is the best rescue treatment, and it has an effect on all borer stages. Micro-infusion is an invasive system of delivery that requires
drilling holes in the trunk every other year. The process wounds the trees, and it can potentially compromise tree health. It is the most expensive of the three control
options. When using systemics, the following criteria are assumed: weather conditions and moisture levels are suitable for optimum uptake and translocation of the
product; during a dry period, pre- and post- treatment irrigations will be provided; the treatment tree has no structural defects, wounds, or root limitations that could
adversely impact optimum product movement within the tree.
|If you have concerns regarding EAB beyond the scope of this fact sheet, call our office for additional assistance: (219)365-6778
For more information on EAB in Indiana, visit: www.extension.entm.purdue.edu/EAB
or call the Indiana Department of Natural Resources invasive species hotline: 1-866-NO EXOTIC
For more information on EAB in Illinois, contact the Morton Arboretum Plant Clinic at 630-719-2424 or www.mortonarb.org
For more information on the national level, visit: www.emeraldashborer.info or na.fs.fed.us/fhp/eab/
P.O. Box 480 St. John, IN 46373
Fax (219) 365-1430