The Little Green Bug
By
Bradley Schowalter
Did you know that the emerald ash borer’s larvae do almost all the damage to the
trees?The emerald ash borer is spreading fast. We must stop this invasive beetle!
The emerald ash borer is native to Asia. It probably came to the U.S on solid wood packing
material, such as crates, or pallets carried on cargo ships and airplanes coming from Asia. The
emerald ash borer or EAB is an exotic beetle that was discovered in southeastern Michigan near
Detroit in the summer of 2002. EAB was found in Illinois in 2006, Wisconsin, in 2008,
Minnesota in 2009, and Iowa in 2010. EAB has been found in many other states. EAB must be
stopped or it will keep spreading.
EAB has killed tens of millions of ash trees in Michigan, Illinois, Minnesota, and
Wisconsin. It has also killed trees in many other states. Without ash trees, we couldn't make
professional baseball bats, furniture, tool handles, and for some people, it makes great firewood.
The emerald ash borer has a one-year life cycle, but it could take two years to complete
its life cycle in a colder climate. Adult beetles are active during the day from mid-June to midAugust. Their eggs are deposited individually in bark crevices on the trunk or branches and hatch
in seven to ten days. After hatching, the larvae chew through the bark and feed on the outer
sapwood for several weeks. Feeding is complete in autumn and pre-pupil larvae make shallow
chambers in the outer sapwood or bark over winter. Adults emerge headfirst through a d-shaped
exit hole that is 3 to 4 mm in diameter. The larvae cause almost all of the damage to the tree.
They do this by making it so the tree can’t transport water and nutrients.
The adult beetles are slender and a ½-inch long. Males are slightly smaller than females.
Their color varies. The adults are usually bronze or golden green overall with metallic emerald
green wing covers. The top of the abdomen and under the wings is metallic purple red and can be
seen when the wings are spread apart.
Larvae are approximately one inch in length. They are white or cream colored. The
body is a flattened and bell shape. Their head is brown. Its head is mostly retracted into the body
and only the mouthparts are visible. The abdomen has a pair of brown, pincer-like appendages on
the last segment. The adult beetle doesn’t do much damage to the ash trees.
Insecticides that can control EAB fall into four categories. These categories are systemic
insecticides that are applied as soil injections; drenches systemic insecticides applied as trunk
injections, systemic insecticides applied as lower trunk sprays, and protective cover sprays that
are applied to the trunk main branches. These insecticides protect your trees and stop the
Emerald Ash Borer from killing them.
Wisconsin has spent four million dollars in federal money and 400,000 dollars in state
funds through a three-year period that ends this summer, trying to stop EAB from spreading any
farther. State and federal rules control the movement of ash materials, such as firewood,
seedlings, logs, mulch, and products made from ash. If you suspect an emerald ash borer
infestation, please report it by calling the emerald ash borer Hotline at 1-800-462-2803.
EAB is an invasive beetle. If we don’t stop it, it will kill all of our precious ash trees.
We need to stop this vicious beetle!