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Town Talk: You ask, we answer: Emerald Ash Borer

Is Brown County quarantined due to Emerald Ash Borer?

Yes! Emerald Ash Borer (EAB) is a non-native, thin, bright metallic, emerald green colored beetle about ½” long. Adults feed on ash tree foliage. Adult borers lay eggs on ash tree bark. As the eggs hatch, the larvae bore through the bark and feed in the ash tree’s cambium. The cambium contains the vessels between the bark and heartwood that move water and nutrients to and from the tree’s crown and roots. The larval feeding galleries disrupt the movement of water and nutrients and lead to the death of the tree.

Signs of a possible infestation are canopy thinning, excessive sprouting, woodpecker damage, S-shaped galleries or channels beneath the bark, and very small D shaped holes in the bark. Native ash borers leave very small round holes in the bark and also leave larval galleries beneath the bark but usually do not cause the death of healthy ash trees.

The spread of emerald ash borers can be slowed but not stopped. Our ash trees have no defense against the emerald ash borer. We can work now to lengthen the time we have to replace our ash trees and spread the costs of removals over a longer time span. Actions we can take to respond and manage emerald ash borer are:

1. Stop planting ash trees.

2. Plant other tree species to take the place of ash trees that will be lost.

3. Remove declining or hazardous ash trees now.

4. Treatment of ash trees with systemic insecticides may lengthen the lives of cherished trees. Systemic insecticides are available through local nurseries and professional treatments are available from local tree services. Treatments are effective for healthy or lightly infested trees. This is a growing season treatment.

5. Get non-ash firewood from local sources and burn all of it during the heating season.

6. Infested trees should be removed during the dormant season. The Minnesota Department of Agriculture recommends that no removals and transport of ash trees or tree trimmings be done between May 1 and September 30 as this is when EAB adults are emerging from infested trees.

Steps 1-3 are already being practiced on New Ulm city owned lands. Researchers continue to look into insect predators that may control the borer and to evaluate trees in infested areas that survived borer attacks to see if they have genetic resistance to the borer.

A new infestation of emerald ash borer was discovered in New Ulm recently. Brown County is now quarantined to help slow the spread of this serious pest of all species of ash trees in Minnesota. The Minnesota Department of Agriculture (MDA) quarantine prohibits the movement of all ash products, logs, removal debris, and all deciduous (hardwood) firewood out of a quarantined area without an MDA permit.

MDA hosted an EAB Open House on October 8. Two representatives outlined EAB life cycles, symptoms, management recommendations, and future MDA and possible local actions to combat EAB. Their EAB web pages, www.mda.state. mn.us/eab, have very complete information on all facets of EAB and EAB management. MDA will do a survey in New Ulm this fall/winter to gauge the extent of our infestation.

The City of New Ulm website, www.newulmmn. gov, has many valuable resources on emerald ash borer and tree management. To find them click on “Site Map”, scroll to “Tree Commission”, click on “Emerald Ash Borer (EAB) and one can find:

• Emerald Ash Borer Preparedness Plan

• Distinguishing Ash from Other Common Trees

• Signs and Symptoms of Emerald Ash Borer

• Frequently Asked Questions Regarding Potential Side Effects of Systemic Insecticides Used to Control Emerald Ash Borer

• Emerald Ash Borer Treatment Guide

Clicking on “Tree Commission” will bring one to a page that lists:

• Boulevard Tree and Shrub Policy

• Tree Permit Questions and Answers

• Diseased Tree Removal Program

• Boulevard Tree Planting Reimbursement Program

• Tree Pruning, Removal and Planting Permit

• ReLeaf Reimbursement and Removal Application

List of Licensed Tree • Services for City of New Ulm

• Tree Advisory Commission members

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Editor’s Note: The City of New Ulm presents a weekly column highlighting activities in different departments in the city government. Once a month the city will answer questions from readers. Questions on New Ulm city issues can be sent to comments@ci.new-ulm.mn.us.

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