Destructive Tree Insect Beetle: The Emerald Ash Borer

Emerald Ash Borer

There is a division of the United States Department of Agriculture entitled APHIS, which stands for The Animal and Plant Health Inspection Service. This agency oversees protecting animal health, animal welfare, and plant health. APHIS collaborates with other agencies to protect U.S. agriculture from invasive pests and diseases. One if these invasive pests is the Emerald Ash Borer.

Much has been written about this incredibly destructive insect that has decimated the ash tree population for much of the Midwest and Northeast U.S. It is slowly spreading farther west and north and has now been found feeding on trees in Winnipeg, Manitoba, Canada. Each month, APHIS releases an updated Emerald Ash Borer Detection Map. This invasive insect has slowly pushed out from its initial infection site in the Detroit, MI area.

What is this Green, Metallic Beetle?

Emerald Ash Borer was first identified in 2002. The adults do little damage to trees, occasionally nibbling on leaves of ash trees. The damage comes from the feeding of the larva, which feeds the inner bark of ash trees and disrupts the trees’ ability to transport water and nutrients to the tree. Emerald Ash Borer is currently found in 31 states* as well as the Canadian provinces of Ontario, Quebec and Manitoba and has literally killed millions of ash trees and has cost many cities millions of dollars in tree removal costs or control methods.

The adult Emerald Ash Borer beetles are metallic green and about 1/2-inch long and they only attack ash trees. The female lays individual eggs on ash trees between layers of outer bark and in cracks and crevices of the trunk. The eggs hatch in about two weeks and the larvae bore into the cambium layer of the tree and begin feeding on the phloem tissue. The typical life cycle lasts one to two years.

As the larvae feed, they etch serpentine trails that are called galleries. The larvae mature during September, overwinter in small pupation cells and may exit the tree or can feed for another summer the following year before reaching maturity.

One aspect of the Emerald Ash Borer life cycle that makes early detection difficult is that the egg laying often occurs in the upper canopy of the tree, making it difficult to find the D-shaped exit holes of the adults. Look for weak and thinning in the upper canopy, branches with yellowing leaves, sucker growth on limbs and trunks, bark splits, and D-shaped exit holes on the trunk.

Treatment for Emerald Ash Borer

There are treatments available for Emerald Ash Borer which require carefully timed applications of insect control materials that are either injected into the surrounding soil or directly into the cambium layer of the tree through an injection process.

If you suspect that your ash trees may be suffering from Emerald Ash Borer damage, contact your local Spring-Green. Unfortunately, by the time the canopy begins to thin or sucker growth occurs on the main branches is seen, it is often too late to effectively treat for the insect. Often, tree removal is the only choice.

*According to the United States Department of Agriculture: Alabama, Arkansas, Colorado, Connecticut, Delaware, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Nebraska, New Hampshire, New Jersey, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, South Carolina, Tennessee, Texas, Virginia, West Virginia, and Wisconsin

Where Do Insects Go in Winter? Winter and its Effect on Insect Populations

Winter Trees

I’ve been asked many times what impact a really cold or mild winter has on insect populations. It is a good question and one that begs a better answer than the actual truth… a really cold or mild winter does not make much of a difference for the survival of insect populations.

Insects have been around for millions of years and have endured all sorts of weather patterns. Because of this they have adapted to survive and persist despite the winter weather.

But Where Do Insects Go in the Winter?

Many insects simply enter a dormant stage called diapause. It can occur in winter, or summer, and is a fairly common occurrence. Many insects have the ability to dehydrate themselves during the winter. Even the insects that may sneak into your house in the fall to escape the winter often dehydrate themselves.


If you’re wondering where insects go in the winter, check your windows. They hide on window sills and window edges as they wait for the return of warmer temperatures.

As a result, you may see a fly or Multi-colored Asian Lady Beetle flying around your house on a warm, sunny day in January. The warmth of the sun coming in through the window allows them to re-hydrate and they will then attempt to fly around. If you’ve seen this, you may have noticed that the insect flies in a zig-zag pattern, and that they are very easy to catch in mid-flight.

What Effect Does Winter Have on Insects like the Emerald Ash Borer?

Many people thought the recent “Polar Vortex” of 2014 would reduce Emerald Ash Borer populations. While it may have reduced the populations in some areas in the far north, the overall average mortality rate was only about 5% or so. This is because the cold weather didn’t last long enough to result in a greater impact on populations. Also, even in cold weather the sun will warm-up a tree enough so that the larva stays warm and is protected from the bitter cold.
The reality is that each year we will never know what will happen during the months of winter. The one thing that we do know is that insect populations are not greatly affected by the winter weather. And yes, they will still be a problem in lawns and landscapes when spring comes along!

Spring-Green offers an array of insect control services, from flea and tick control and mosquito control in certain markets to perimeter pest control, which prevents spiders, ants and other critters from entering your home. Get in touch with your local Spring-Green to find out more about our guaranteed insect control services.

Why are There Still Leaves on my Tree?

I recently received a question from a person asking why their ash tree still has leaves on it at this late date. The person stated that some leaves were turning brown during the summer and that they figured it was due to the drought that much of the Midwest experienced this year.

There are some trees that keep leaves that turn a fall color for a long time. Some of them remain on the tree all the way until spring. Ironwood, certain oaks and beeches are a few of the trees that keep their leaves on for a longer time than most other deciduous trees. Sometimes this is just the quality of the tree and sometimes it can be the result of some other stress factors.

In the case of the tree in question, the first clue is that it is an ash tree and the leaves started turning brown in the summer. There is a good possibility that the tree has been inhabited by Emerald Ash Borer and the dying leaves are the result of the feeding habits of the insect. Emerald Ash Borer is a destructive insect that has killed several million trees throughout Michigan, Ohio, Indiana, Illinois and many other states. The larval stage of the Emerald Ash Borer feeds on the soft tissue of the cambium layer, cutting off the supply of nutrients and water to the tree often resulting in the death of the entire tree. In this picture, you can see the result of the feeding by the larvae. You can also see how the bark easily peels away, leaving behind a complex pattern of feeding tunnels.

If you suspect your ash tree has Emerald Ash Borer, you need to have it inspected by a professional tree company or arborist. Some of the clues that the tree may be inhabited would be leaves that do not fall off in the fall, branches that are dying and the presence of “flagging”, or a large congregation of branches growing out of the trunk or major branch located at the base of a dead or dying branch.

There are treatments available that will help combat this destructive insect. Success depends on the extent of the damage.  In some cases, the only solution is to remove the tree.

Contact your local Spring-Green office and ask for someone to come out and inspect your ash tree to provide you with the best approach to saving it.

First Detector Forest Pest Training

Earlier this week, I attended the First Detector Forest Pest training program put on by the University of Illinois Extension Service in Springfield, IL. It focused on different invasive species that threaten native plants or have the potential to cause major financial impacts on local economies in an effort to control these pests.

The first pest discussed was the Emerald Ash Borer which is causing the death of literally millions of trees in the Midwest and is moving outward from there. Currently, it can be found in 15 states and in Canada and has the potential to make its way across the entire continental U.S.

The second forest pest discussed is known as Thousand Cankers Disease, which has the potential to attack various species of walnut trees. This disease is produced by the combined activity of a canker producing fungus and a boring beetle called a Walnut Twig Beetle. The tiny, about 1 mm in length, beetle is covered with tiny hairs that can trap the spores of the disease. When it bores into the tree to lay eggs, the spores dislodge and begin infecting the tree. This disease has devastated plantings of Black Walnut in several western states and has now been identified in parts of Tennessee, Virginia and Pennsylvania.

This disease has the potential to seriously affect the timber industry in Illinois and surrounding states. I learned that the value associated with the harvesting of Black Walnut trees in Illinois ranges from $13,000,000 to $18,000,000 a year. Missouri, a close neighbor to Illinois, is one of the largest producers of walnut wood products and the spread of Thousand Cankers disease could have an even greater financial impact on that state.

We also discussed three major invasive weeds – Oriental bittersweet, Japanese Stiltgrass and Giant Hogweed. Of the three, Giant Hogweed seems to be the one that is of most concern. Giant Hogweed grows 8 to 15 feet high with very large leaves and giant flowers called umbels. The sap of this plant is photo-reactive and if it gets on one’s skin and then is exposed to UV or sunlight, severe blistering and skin rashes can occur. It is like the reaction to Poison Ivy, but on a much greater scale.

An important part of the course was how to scout for these problems and how to submit samples. I am glad that I now know more about these problems and will definitely be on the lookout for them.