Above / In autumn, ash trees often create a golden canopy along the streets in Naperville.
Update, March 3, 2019 / In recent weeks, folks have been enthusiastic about the thought that this winter’s deep freeze in Illinois might have killed off the Emerald Ash Borer.
Note. The time to treat for Emerald Ash Borer is spring & summer.
Resources and everything you might want to know about the Emerald Ash Borer
A little history—in the summer of 2002, the adult Emerald Ash Borer, an exotic-looking beetle about 1/2 inch long with a shiny iridescent coat, was discovered in southeastern Michigan near Detroit. And now, the unwelcome pest has found a home in Naperville, chewing and burrowing its way from one ash tree to the next.
The Emerald Ash Borer likely arrived in North America on solid wood packing material carried in cargo ships or airplanes, originating in its native Asia sometime in the 1990s—some arborists think maybe even a decade earlier.
These sorts of things have been happening for centuries. In the 19th century, a little louse called phylloxera made its way to Europe from eastern American shores killing almost all of the grape vines in Europe—they are kinda like the pesky grubs that destroy our green lawns. There has always been a sense of mutual-destructive-evolutionary-reciprocity. European merchants returned the favor with a blight fungus they unwittingly shipped from Asia which killed almost all the American chestnut trees around 1900. The fungus probably survived the Pacific voyage on a moist wooden crate. Today, most chestnuts for eating are grown in South Korea—go figure.
Since the Emerald Ash Borer was discovered in Michigan, the unwanted beetle has continued to extend its devastation roughout the Midwest. The insect also is spreading within states currently infested with EAB, and most recently was detected in Iowa— raising the total number to 15 states and two Canadian provinces with confirmed infestations in North America. It’s been found in Illinois (since 2006), Indiana, Ohio, Minneapolis-St. Paul area, as well as in southern Wisconsin, Maryland, Missouri, north-central Kentucky, New York, West Virginia, Virginia, Pennsylvania and Washington, D.C, Iowa, Ontario and Quebec.
Naperville first discovered ash tree infestations in 2008 in the southwestern section of the city. In 2010, reports of the EAB were collected throughout the entire city. This insect is very hard, if not impossible, to detect in the early stages of infestation— most of the time it takes 2-5 years before a tree shows stress.
Why you should care about your ash…
The adult beetles feed on ash foliage but cause little damage. The larvae (the immature stage) find their nourishment on the inner bark of ash trees, disrupting the tree’s ability to transport water and nutrients, and that’s damaging.
If you live within a 15 mile radius of a known infestation, you need to show concern for your ash tree. It is likely that by the time foresters discover these new areas, the insect may have been present there for 3-5 years or longer. If you have ash trees that are important to you and you do not want to lose them, then you will need to do something about it soon. Preventative treatments are the key to successfully saving your ash trees way before they show signs of infestation.
In 2010, when this info was first posted on the PN website, ash trees were the most numerous species in Naperville’s parkway tree inventory, comprising more than 15,500 of the city’s urban forest. That was 29 percent of the city’s parkway tree inventory, according to folks in the Department of Public Works.
In April 2012, that number in Naperville more accurately is reported to be 16,300 parkway trees.
Today the planting of ash trees (white ash and green ash trees are native to Illinois) is not allowed on any Naperville parkway and the species will not be approved on private property landscape plans reviewed by the city.
Did you know? In Naperville, trees found to be infested must be removed and chipped in accordance with Department of Agriculture disposal protocol. If the tree is on private property, the owner is responsible for the cost of taking the tree down usually within 10 days of notification by certified letter.
Characteristics of Ash Trees
- Ash trees feature compound leaves made up of small, glossy green leaflets
- Leaves, twigs and branches grow in opposite pairs
- Bark of mature ash trees is gray and furrowed, often appearing in a diamond pattern
- Some ash trees will produce small “canoe paddle-shaped” seeds
- Ash trees are quick to grow and relatively inexpensive
- Ash trees stand up to salt in winter
Enlightening read about progress!
In the August 2010 issue of Arbor Age, Dr. Frederic Miller of Joliet (Ill.) Junior College and the Morton Arboretum is quoted in the story titled “Rise from the Ash” by John Kmitta. Miller said that some municipalities, which are heavily ash, could lose one- third of their tree canopy due to EAB if left untreated.
Much scientific research is in the works to try to save this fast-growing tree. With education and awareness, arborists can continue to develop new and improved management tools, and here’s hoping that long-distance spreading through firewood can be minimized. Alert! Be sure to know the local source of any firewood you might purchase or have delivered.
Life cycle of Emerald Ash Borer
Emerald ash borer emerges as a flat, rust-colored egg, slightly bigger than the period at the end of this sentence. A single female will lay 50 to 80 eggs at a time on the bark of an ash tree in summer.
A skinny creamy white larva grows, burrows into the bark, and begins eating the living wood. In the process, it cuts off the conduits that carry water and nutrients from roots to leaves and “sun-made” sugars from leaves to the rest of the tree.
In spring the larva morphs into a pupa. In early summer the pupa develops into an adult beetle. Two to three weeks later, the insect bores out of the bark, leaving a telltale D-shaped escape hole. The deep green-colored adult (about one-half inch long and one-eighth inch wide) with a purplish belly flies off to mate and begin the cycle again. The adults don’t live long.
Trees can survive for two to three years until destructive borers finally take over. Enough larvae, enough serpentine trails, and the flow of water and nutrients inside the tree is completely severed. Twigs, branches, and ultimately the whole tree die.
If you suspect you have EAB in your ash tree, contact your city forester immediately. In Naperville, that phone number is (630) 420-6095.
Pay Attention via References
Here are Web sites with info about the pesky insect:
- Call the Morton Arboretum Plant Clinic at (630) 719-2424 or visit online at Morton Arboretum Plant Clinic
- The Emerald Ash Borer INFO
- To know how close this insect is to threatening your ash trees, you can find a detailed list of Confirmed Infested Locations at the Illinois Department of Agriculture’s Web site.
- Emerald Ash Borer (Michigan Department of Agriculture
- Emerald Ash Borer (USDA Forest Service)
- City of Naperville: Emerald Ash Borer
- Find a local Certified Arborist HERE. (See a video, too!)
- Call for a free diagnosis & cost analysis: (630) 717-0763
- Also find certified arborists locally at The Care of Trees, Davey Tree Service and Horticulturalist Carl Schultz.
Stay Informed & Learn
- National EAB Hotline: (866) EAB-4512
- City of Naperville Forestry Section: (630) 420-6095
- Morton Arboretum: (630) 719-2424 or visit www.mortonarb.org
- The Emerald Ash Borer INFO
In 2010, PN sent these photos taken at a Naperville property to a Master Arborist for an assessment of the condition of the 20-year-old ash tree.
I could zoom in and actually see where the woodpeckers not only knocked all these chunks of bark off, but then they tap with their beak and claw with their feet – feeling for vibrational changes in the bark that tell them EXACTLY where the EAB larvae are under the bark. Then when they locate one, they peck at that spot making a round hole with their beak and remove the insect and eat him. They can make quite the mess. But without them we wouldn’t know sometimes that the EAB are even there.
—Wayne White, Master Arborist
During a 12-hour period, a woodpecker fed on the EAB larvae, stripping the tree of some bark and leaving slivers all around the base of the ash tree. The slivers resembled potato peels and created quite a mess.
Shortly after we shot the photo of the woodpecker on a feeding frenzy in this ash tree (late summer 2010), a hawk found a perch in the same tree for quite some time. We couldn’t help but wonder if the hawk had fed on the woodpecker.
The tree in the above photo, located on private property, is no longer standing. In 2010, the tree was removed and chipped at the owner’s expense for $250. It’s recommended to get several estimates if trees must be removed as there is no set price.
In 2012, the science is about to catch up with the pesky little EAB.
How to prevent spread of EAB and save your ash here, there and everywhere
Use only local firewood. To avoid being an insect carrier along the highway, buy or cut firewood where you’ll burn it—locally.
Only purchase wood from a local business; not from an unknown door-to-door firewood salesperson with wood on a pick-up. And if you cut down an ash tree on private property, tell the city forester and have the tree chipped into mulch.
Chipping and removal must be in accordance with Department of Agriculture disposal protocol.
Watch your tree. If you see an ash tree with D-shaped exit holes or lots of dead branches at the top (die back) and sprouts from the trunk, contact the Department of Public Works Forestry Section at (630) 420-6095.
If your private property tree is diagnosed with the infestation of EAB, please contact the city with this information so they can keep abreast of the situation.
Also note that the beetles are short-lived in the late spring/early summer, so they’re not around in fall, but their larvae lives under the bark. It’s unlikely to find one of the flying beetles in the fall or winter.
Don’t go ballistic. If you want advice on your ash trees, choose an International Society of Arboriculture (ISA)-certified arborist or tree inspector. We have found that the certified arborists we’ve contacted appreciate the opportunity to share what they know to fight this unwanted pest that is destroying millions of trees.
Think. Consider planting saplings of another species that can take over if you eventually lose your ash. Find suggestions and information on tree planting, grants, or forestry for more suggestions on trees and shrubs that aren’t susceptible to the ash borer. Think about diversity for your landscape.
Save seeds. Scientists are collecting ash seeds for the National Center for Genetic Resources Preservation in Colorado. To learn how you can help, visit ashseed.org
Talk about EAB! Spread the news and warnings about Emerald Ash Borer to everyone you know in the Midwest. Share this Positively Naperville Web page story with friends and neighbors.
Recently public service announcements on the radio have advised never to transport fire wood that might be infested with the EAB.
Help save your ash! Questions? Call (630) 420-6095.