Beware of the Emerald Ash Borer
Residents need to beware of a little
bug named the Emerald Ash Borer. This pesky little beetle is capable of
decimating ash populations wherever it pops up. Although the Borer has
not been found in Illinois, it was discovered for the first time in
North America , feeding on ash trees in southeastern Michigan. The
beetle’s natural habitat is eastern Russia, northern China, Japan, and
All species of North American Ash appear to be susceptible to invasion.
If detection of the Borer is not caught in the early stages, and
infestation is high, the ash tree will not recover and will die.
However, if the beetle is detected early, pesticide application,
although not a guaranteed cure, may improve the ash tree’s chance of
The Emerald Ash Borer is bright green in color and approximately 1/2
inch long by 1/8 inch wide. To view a picture of the Emerald Ash Borer
you can access the Village’s web site at www.palospark.org.
When invasion occurs, the Borer penetrates the bark, attacking the area
known as the xylem, which is the water and nutrient conducting tissue in
trees. Once an ash becomes heavily infested, canopy dieback will occur,
which will usually start at the top of the tree. After initial
infestation, 1/2 of the canopy will die in the first year. All of the
canopy will be dead within two years of infestation.
There are a couple of signs to look for to see if your ash tree might
have the Emerald Ash Borer. Investigate the base of your ash tree.
Although difficult to see, the adult beetles leave a “D” shape exit hole
in the bark, roughly 1/8 inch in diameter. The beetles emerge in June,
so keep a close eye out in the early summer. Also, you will notice rapid
decline in an infected ash tree between July and October, during which
larval feeding is most active, so contact a professional arborist.
If anyone has reason to believe that their ash tree might have Emerald
Ash Borer contact the Village or the Illinois Department of Agriculture
for further investigation.