- Emerald Ash Borer Alert
- What is the Emerald Ash Borer?
- Identification of the Emerald Ash Borer
- Emerald Ash Borer Signs and Symptoms
- Treatment & Control
Emerald Ash Borer Alert
The Emerald Ash Borer pest is now present in all counties of our work area. We are seeing the negative effects much sooner than we expected, and this spring will expose the number of dead or declining Ash trees in your area.
If you have a healthy Ash trees in your landscape or your yard, on a city or village green space, we strongly recommend that it be treated before the borer damage is evident. Untreated trees will likely be infested in the next few years, with a 3-5 year life expectancy after infestation.
In most cases, we are using a treatment that has been proven to give two years of control. If your Ash trees appear to be healthy, we highly recommend you contact us for an evaluation to see if they are good candidates for treatment to prevent infestation by the borer. Treatments will be done in late spring and early summer for the most effective control.
Dead or dying Ash trees, or any dead tree should be removed in a timely manner. The longer they are left standing, the more hazardous they become, and hazardous trees are typically more expensive to remove.
Not sure if your tree is an Ash tree? Review this Ash Tree Identification Guide
What is the Emerald Ash Borer?
A beetle from Asia, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), was identified in July 2002 as the cause of widespread ash (Fraxinus spp.) tree decline and mortality in southeastern Michigan and Windsor, Ontario, Canada. Larval feeding in the tissue between the bark and sapwood disrupts transport of nutrients and water in a tree, eventually causing branches and the entire tree to die. Tens of millions of ash trees in forest, rural, and urban areas have already been killed or are heavily infested by this pest.
A. planipennis has been found throughout Michigan, across much of Ohio, and in parts of Indiana, Illinois, Maryland, Missouri, Pennsylvania, Virginia, West Virginia and Wisconsin. The insect is likely to be found in additional areas as detection surveys continue. Evidence suggests that A. planipennis is generally established in an area for several years before it is detected.
The broad distribution of this pest in the United States and Canada is primarily due to people inadvertently transporting infested ash nursery stock, unprocessed logs, firewood, and other ash commodities. Federal and state quarantines in infested states now regulate transport of these products.
Identification of the Emerald Ash Borer
Adult beetles are generally larger and brighter green (Fig. 1) than the native North American Agrilus species. Adults are slender, elongate, and 7.5 to 13.5 mm long. Males are smaller than females and have fine hairs, which the females lack, on the ventral side of the thorax. Adults are usually bronze, golden, or reddish green overall, with darker, metallic emerald green wing covers. The dorsal side of the abdomen is metallic purplish red and can be seen when the wings are spread (Fig. 2). The prothorax, the segment behind the head and to which the first pair of legs is attached, is slightly wider than the head and the same width as the base of the wing covers.
Larvae reach a length of 26 to 32 mm, are white to cream-colored, and dorso-ventrally flattened (Fig. 3). The brown head is mostly retracted into the prothorax, and only the mouthparts are visible. The abdomen has 10 segments, and the last segment has a pair of brown, pincer-like appendages.
Emerald Ash Borer Signs and Symptoms
It is difficult to detect A. planipennis in newly infested trees because they exhibit few, if any, external symptoms. Jagged holes excavated by woodpeckers feeding on late instar or prepupal larvae may be the first sign that a tree is infested (Fig. 6). D-shaped exit holes left by emerging adult beetles may be seen on branches or the trunk, especially on trees with smooth bark (Fig 5). Bark may split vertically over larval feeding galleries. When the bark is removed from infested trees, the distinct, frass-filled larval galleries that etch the outer sapwood and phloem are readily visible (Fig. 7). An elliptical area of discolored sapwood, usually a result of secondary infection by fungal pathogens, sometimes surrounds galleries.
As A. planipennis densities build, foliage wilts, branches die, and the tree canopy becomes increasingly thin. Many trees appear to lose about 30 to 50 percent of the canopy after only a few years of infestation. Trees may die after 3 to 4 years of heavy infestation (Fig. 7). Epicormic shoots may arise on the trunk or branches of the tree (Fig. 8), often at the margin of live and dead tissue. Dense root sprouting sometimes occurs after trees die.
A. planipennis larvae have developed in branches and trunks ranging from 2.5 cm (1 inch) to 140 cm (55 inches) in diameter. Although stressed trees are initially more attractive to A. planipennis than healthy trees are, in many areas all or nearly all ash trees greater than 3 cm in diameter have been attacked.
Treatment & Control
According to many University studies, trunk injection is the most effective method of treating for EAB. That's why we use it. The formulation that Hendel’s Affordable Tree Care & Landscaping has proven most effective is ArborJet's TREE-äge formulation, with the active ingredient Emamectin Benzoate. This formulation is registered in Indiana, Ohio and Kentucky, and of course covers the Greater Cincinnati tree service area.
We use arborjet products to eradicate and prevent EAB. It is a drill-plug-inject method, and is guaranteed two to four years depending on the contract.
Unlike spraying or soil drenching, Arborjet’s closed system injects directly into the tree, protecting our customers, the applicator, and the environment.