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Emerald Ash Borer04-01-03 | News

Emerald Ash Borer

ANLA Quarantines for Emerald Ash Borer

The American Nursery & Landscape Association (ANLA) has urged U.S. Secretary of Agriculture Ann Veneman and the Department of Agriculture to move swiftly to establish a federal quarantine for the emerald ash borer (Agrilus planipennis), and to take all steps necessary to compensate ash tree nursery stock producers located in the quarantine zone as defined by a new federal regulation.

ANLA informed Veneman that the emerald ash borer, which was discovered infesting roughly 2,000 square miles in southeastern Michigan, poses a grave threat to shade tree producers from coast to coast. The pest is from China and other parts of Asia. It likely arrived in Detroit infesting wood packaging. Unless management options are successfully developed, the pest will eliminate ash trees from production and landscape use. Ash is estimated to be the single most important shade and landscape tree in the northern United States. It is also an economically important forestry species, and a valued component of ecosystems across most of the U.S.

The damage identified in this photo are the ?EUR??,,????'??D?EUR??,,????'?? shaped exit holes in the bark of ash trees left behind by the adult beetles. The hole is approximately 1/16-inch in diameter.

ANLA believes that a federal quarantine could set strong and uniform rules for slowing or containing the spread of the pest from southeastern Michigan; ensure adequate safeguards are in place for international trade with Canada, where the pest also has been detected; and facilitate public and private-sector research funding; ANLA also supports compensating a small number of nursery growers trapped in the quarantine area and unable to market their ash nursery stock. Compensation is warranted for these producers, since they have lost crops and sales without warning.

?EUR??,,????'??USDA and the states must mobilize to slow the spread of this devastating pest,?EUR??,,????'?? said ANLA President Wayne Mezitt, Weston Nurseries in Hopkinton, Mass. ?EUR??,,????'??The affected nursery producers in southeastern Michigan should also be compensated for tree losses, since this pest?EUR??,,????'???s introduction results from a failure of USDA?EUR??,,????'???s inspection system?EUR??,,????'?? he added.

ABOUT THE BEETLE

The following information is from the Michigan Department of Agriculture, the Michigan Department of Natural Resources, Michigan State University and the U.S. Department of Agriculture APHIS and Forest Service.

Where did this Emerald Ash Borer come from? At this point no one knows specifically how it arrived in Michigan. It is an exotic pest species. The natural range of Agrilus planipennis, or the Emerald Ash Borer, is eastern Russia, Northern China, Japan, and Korea.

WHAT IS THE ASH BORER?

The Emerald Ash Borer, Agrilus Planipennis, is an exotic insect pest that has been discovered in dying ash trees in Southeast Michigan.

An ash tree affected by the beetle in slow decay.

What types of trees does the Emerald Ash Borer affect? To the best of our knowledge it has only been found on ash trees, hence its name. Trees in wood lots as well as landscaped areas are affected. For the most part, affected trees appear to be at least 2 inches in diameter and larger.

Where has it been found? To date, infested trees have only been found in Livingston, Macomb, Oakland, Washtenaw and Wayne Counties. Inspections are continuing in other areas of the state.

What symptoms does a tree infested with the borer exhibit? Infested trees exhibit top-down dieback typical of other phloem borers such as two-lined chestnut borer. It has been observed that one-third to one-half of the branches may die in one year. Most of the canopy will be dead in two years. Affected trees may have vertical splits in the bark 2-4 inches long. Often dense sprouting of shoots can been found arising from the trunk or roots. Although difficult to see, the adult beetles make a ?EUR??,,????'??D?EUR??,,????'??-shaped exit hole in the bark, roughly 1/16 inch in diameter.

What do Emerald Ash Borers look like? The adult beetle is dark metallic green in color, 1/2 inch in length and 1/16 inch wide.

(Left) The exit point of an ash borer is identified here. (Right) More damage from the pest can be seen in the bark of this ash tree.

What is the life cycle of this borer? The beetle appears to have a one-year life cycle. Adults begin emerging in late May with peak emergence in mid-June. Egg laying occurs soon after adult emergence. After hatching, the borer goes through several larval stages, overwinters as a larva, then pupates in late spring.

HOW IS THE PEST SREAD?

The ash borer can be spread through movement of infested trees or in logs and firewood. The borer is a good flier, although it is doubtful that it could fly long distances. Most likely, local spread would occur by movement of infested material and adult flight, while long distance spread would occur due to movement of infested material or other human activities.

How long has the Emerald Ash Borer been in Michigan? No one knows for sure. Experts feel that it may have been in the Detroit area as long as five years, based on the age of trees affected and when tree dieback was first observed.

Does it only attack dying or stressed trees? While many of the trees affected by this ash borer appear to have been stressed by drought, disease or poor soil, in many instances healthy trees were also infested and killed by the borer.

What are other insects may attack ash trees? It is not uncommon for diseases or dying trees to be attacked by secondary borers once the tree is weakened. Some of the secondary pests attacking ash include larvae of various native cerambycid beetles, clearwing moths or even certain Diptera species.