Emerald Ash Borer Information
Description
The Emerald Ash Borer (EAB) is an invasive pest introduced from Asia that attacks ash trees (Fraxinus spp.) This metallic wood boring beetle was found in Detroit, Michigan and Ontario, Canada in 2002, and has continued to spread into neighboring states, threatening to eventually spread across the U.S. and Canada. The adult is a small, metallic green beetle only 10-15 mm in length and about 3 mm in width. The larvae live under the bark of the tree and feed in the vascular cambium. The adults typically emerge around June, leaving D-shaped exit holes in the bark. They briefly feed in the canopy before reproducing and laying eggs in the twigs and branches.
Symptoms
Dieback of the canopy above the site of infestation. As many as one half of the branches may die back in one year of infestation. The tree will try to compensate by sprouting new epicormic growth below the level of infestation. The bark may begin to split. Under the bark, larval trails will meander through the vascular cambium. Trees can die within only two years of the onset of symptoms.
What To Do
Arborjet recommends a trunk micro-infusion or microinjection with either IMA-jet (imidacloprid) or TREEäge (emamectin benzoate) using either the Tree I.V. system or the QUIK-jet device. The large vessel transport system in ash trees will rapidly take up injected IMA-jet. TREE-äge is more viscous and will take slightly longer to inject but will provide a longer residual effect. TREE-äge and IMA-jet will kill the EAB larvae inside the tree. IMA-jet can be mixed with MICRO-jet Mixable to provide the tree with insecticide and fertilization in one treatment. See the IMA-jet and TREE-äge labels for dosage rate based on tree size.
When To Do It
Treat ash if EAB is reported in your area. Do not wait for visible dieback in the canopy. There is a significant delay between damage to the vascular cambium and dieback in the canopy. Delaying treatment will result in canopy dieback or tree loss. There are 2 treatment windows for EAB in a given year. Treatment in the spring will prevent the adult beetles from feeding and laying eggs in the tree. Injecting in the summer will kill the larval stage of EAB feeding under the bark. Uptake of formulation is fastest when trees are actively transpiring. Morning applications are best, especially during summer weather. When air temperatures are high or when soil conditions are dry, it is best to postpone injection for better environmental conditions. Monitoring should be a standard component of the treatment program and trees should not be treated more than once annually.
What Will Happen
IMA-jet will kill the EAB larvae under the bark and deter adult feeding on the treated tree. TREE-äge will kill the EAB larvae under the bark as well as adult beetles that feed on the tree. A single application of IMA-jet will provide extended residual control of EAB. The residual control of TREE-age will be longer. Tree recovery from an established infestation is relative to the severity of the infestation at the time of treatment as well as other environmental factors.