Native Ash Trees are in Trouble
the War Against EAB



Emerald ash borer (EAB), Agrilus planipennis (Fairmaire):

Native Ash Trees. (Fraxinus ssp.) (Ash)

A common tree of our forests, landscapes and they line many suburban streets.

However, our these trees are under attack in the Great Lakes and Northeast regions and spreading fast.

Another native tree that is in danger!

It could even become extinct in this country.

It has happened before.

A tree became practically extinct, when the elm tree fell victim to Dutch Elm Disease and died out.

I vaguely remember as those green leafy bowers disappeared completely over the period of a few years, so that today the elm is very rare.

History could very well repeat itself with the ash tree.

EAB Larvae enlarged

Emerald Ash Borer:

An exotic beetle that was discovered in southeastern Michigan near Detroit in the summer of 2002.

(Photo to the right is enlarged so you can get a good view of the larval state if the insect.)

EAB is a member of the metallic wood boring beetle family.

Native of China, Russia, Japan, Korea and other parts of Asia, It attacks all native North American ash trees, regardless of the tree's health.

As with any introduced species, there isn't a natural enemy and this particular insect is on a rampage

Once an Emerald Ash Borer infestation occurs, it kills the tree in 2 to 4 years.

The adult beetles nibble on ash foliage but cause little damage. The larvae (the immature stage) feed on the inner bark or cambium of ash trees, disrupting the tree's ability to transport water and nutrients.

While there are native borers in many of our trees, they don't kill our trees as the EAB does.

EAB's have a different pattern when feeding on the cambium. They go back and forth in a "S" shape in exaggerated patterns. as several borers feed, they cut off the ability of the tree to feed.

The insect probably arrived in the Detroit area, or Windsor, Canada on solid wood packing material carried in cargo ships or airplanes originating in its native Asia.

Emerald ash borer is also established in Windsor, Ontario, was found in Ohio in 2003, northern Indiana in 2004, northern Illinois and Maryland in 2006, western Pennsylvania and West Virginia in 2007, Wisconsin, Missouri and Virginia in summer 2008, and Minnesota in the spring of 2009. Since its discovery, EAB has:

in insects have killed tens of millions of ash trees in Michigan alone, with millions more lost in Illinois, Indiana, Kentucky, Minnesota, Missouri, Ohio, Ontario, Pennsylvania, Quebec, Virginia, West Virginia, and Wisconsin.

They have caused regulatory agencies and the USDA to enforce quarantines (Michigan, Illinois, Indiana, Maryland, Minnesota, Missouri, Ohio, Ontario, Pennsylvania, Quebec, Virginia, West Virginia, and Wisconsin) and fines to prevent potentially infested ash trees, logs or hardwood firewood from moving out of areas where EAB occurs.

Currently, EAB is now in 26 states and two Canadian provinces.

Are you on the list?

Arkansas, Colorado, Connecticut, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Georgia, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Ohio, New Hampshire, New Jersey, New York, North Carolina, Pennsylvania, Tennessee, Virginia, West Virginia, Wisconsin, and most recently Texas. The Canadian provinces of Ontario and Quebec.

Fines can be in the thousands of dollars.

The cost to municipalities, property owners, nursery operators and forest products industries tens of millions of dollars.

Take care of the trees you have and good luck trying to find one at a garden center.

Here are the signs that may indicate the presence of the EAB.

Branch die-back at the top of the tree.

Vertical splits in the bark.

Sprouting on the trunk and at the base of the tree.

Scratched bark from woodpeckers feeding on the larvae.

Distinct 1/8 inch, D-shaped exit holes in the bark.

S-shaped sawdust-packed galleries under the bark.

What is the concern?:

EAB is 100 percent fatal to Fraxinus trees of any size, any age, healthy or unhealthy. The adult beetles nibble on the foliage of ash trees but cause little damage.

The larvae (the immature stage of EAB) cause the most harm by feeding on the inner bark of ash trees.

This disrupts the trees’ ability to transport water and nutrients, causing the tree to starve and eventually die.

A tree that has been attacked by EAB can die within 2-4 years.

EAB Life Cycle:

May to August: Eggs hatch into larvae and tunnel into ash trees

August to October: Larvae feed under tree bark, creating S-shaped galleries

October to May: Larvae over winter under tree bark May to June: Adults emerge leaving D-shaped exit holes; some adults have been seen into August; adults live about three weeks

Mid-May to Mid-August: adults mate then lay eggs in ash bark and the cycle begins all over again.

Dead ash tree from EAB Within a few years, your native tree will look like this one on your right.

Insecticide Options for Controlling EAB

Insecticides used for control of these deadly insects fall into three categories:

(1) systemic insecticides that are applied as soil injections or drenches;

(2) systemic insecticides applied as trunk injections or trunk implants;

(3) protective cover sprays that are applied to the trunk, main branches, and (depending on the label) foliage.

Some can be purchased and applied by homeowners.

Others can be applied only by professional applicators.

Strategies for their effective use are described below.

It is important to note that pesticide labels and registrations change constantly, and can vary from state to state.

It is the pesticide applicator's legal responsibility to read, understand, and follow all current label directions for the specific pesticide product being used.

Bayer Advanced Tree & Shrub Insect Control Imidacloprid Soil drench Mid-April to mid-May.

ACECAP 97 Systemic Insecticide Tree Implants Acephate Trunk implant Mid-May to mid-June.

Seeds from Native species are being preserved for future use in the event that an effective insecticide is eventually developed. Research has begun to identify resistant cultivars and varieties of the ash tree.

Unfortunately, in the case of the elm tree, the cultivars that resisted Dutch Elm Disease lacked the shape and beauty of the American Elm and never became popular.

The ash tree is truly an "endangered species".

Return to the Top of Ash Trees and EAB

Beech Trees, Dieing the Slow Death

Return to Trees of the Northeast and Great Lakes


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