FAQ EAB homeowners

EAB insect websize 2Click on the question to see the answer. Click on the question again to minimize the answer.

Q: What does an EAB beetle look like?

A:  The EAB aduAdult EABlt beetle is a distinctive metallic green, about 1.25 cm (1/2 inch) long.

Q: What is the life cycle of the Emerald Ash Borer?

A: The adult EAB beetle lives only three or four weeks, but the process from egg-to-adult can take one year (or two, depending on the climate). The adult beetles can emergre from ash trees from approximately May to August. From May to September, the beetles mate and lay 60-90 eggs, one at a time, all over the bark of healthy ash trees. When the eggs hatch, the larvae tunnel through the bark to feed on the phloem, which is the vascular tissue just beneath the outer bark where sugars and other nutrients are transported throughout the tree. The larvae feed on the phloem in a repeating S-pattern that disrupts the tree’s vascular tissue and interferes with the flow of water, sugar and other nutrients. The larvae are dormant over the winter, and when the weather warms in the spring, the larvae enter the pupal phase and transform into a sexually mature adults, emerging from D-shaped holes they have chewed through the bark to begin the life cycle again.This educational video provides a good overview: Understanding the Life Cycle of the EAB, 4:05

Q: How does EAB kill ash trees?

A: The larvae of the Emerald Ash Borer feed on the phloem of the ash tree, chewing S-shaped galleries around the tree trunk. The feeding tunnels cut off the flow of sugars and other nutrients within the tree, weakening it. Once feeding tunnels girdle the tree, it’s dead. It doesn’t matter how small or large the ash tree is, the process is the same.

Q: How do I tell which trees on my property are ash trees?

A: There are three kinds of ash trees commonly found in Manitoba. Green ash and black ash are native to Manitoba; Manchurian ash is an Asian tree used as a shade and ornamental tree. Black ash is more commonly found in riverbottom forests and poorly drained areas. Green ash and Manchurian ash are most likely to be found in urban areas, parks and shelterbelts.

Ash leaves (Bugwood)

Ash leaves (Bugwood)

Leaves: The ash has a compound leaf that has a single stem with leaflets attached opposite each other and one at the tip of the stem. A green ash leaf has 5-7 leaflets; a black ash leaf has 7-11 leaflets; a Manchurian ash leaf has 9-11 leaflets.

Branching: Ash trees have a characteristic pattern of

Ash branches

Ash branches

branches and buds that are directly across from each other and not staggered. Look for twigs emerging from the branch opposite each other. The Manitoba maple (box elder) also has opposite branches and compound leaves, but unlike the ash it has only 3-5 leaflets, some of which are lobed.

Bark: The bark of a mature green ash is heavily ridged and furrowed, and has a Ash diamond bark revdistinctive diamond pattern in older trees. Younger trees have smooth grey bark, with some reddish colouring. Black ash bark is a smooth grey with a corky texture. Manchurian ash has a smooth, tan bark, and the rounded canopy of a healthy tree makes it look rather like a lolipop.

Ash seeds revSeeds: Ash seeds are oar-shaped and hang in clusters from branches, which typically remain on the tree until late fall or early winter.

Q: I’m pretty sure I’ve got ash, maple, mountain ash and elm trees on my property. How do I tell the difference between them?

A: Ash tree characteristics are described above. Mountain ash and elm have alternating buds and twigs. You can go to the Natural Resources Canada website on tree identification to learn more.Trees resembling ash copy

Q: My mountain ash is a food source for migrating waxwings. Is it at risk from EAB?

A: No. Mountain ash is not affected by EAB. It is not from the same family as Green, Black and Manchurian ash.

Q: I have ash trees on my property. What are my options?

A: You have two options: save the trees by using an approved insecticide treatment or remove the trees. Large ash trees located near buildings or areas of activity will become hazardous when they die, and could result in property damage or injury. Consult a certified arborist to determine the best option for you. If the tree is on City of Winnipeg property, it is under the care and control of the City. If you wish to treat a City tree, please call 311.

Q: Is it worth the cost to save my ash tree?

A: Property owners have to decide for themselves how much value they place on a particular tree and whether they want to take on the cost of saving it. A well-placed tree can provide shade, privacy, a screen of undesirable views, and can be a thing of beauty in its own right. It can help slow storm-water runoff, limit soil erosion, block wind and reduce noise. Trees improve air quality and provide a home for songbirds. Some trees are treasured for their sentimental or historical value. It’s hard to put a price on all of the benefits, but in the City of Morden in Manitoba, one public tree provides $127 in benefits annually related to stormwater mitigation, energy consumption savings, air quality improvement, carbon sequestration, and aesthetics and other public values. Another factor to consider is the cost of removal. A lovely, mature ash tree that is surrounded by structures or other features may be problematic to remove and will therefore be expensive to remove. The cost of treatment over time may still be considerably less than the cost of removal, and you get to keep and enjoy your tree. It is important to consult with a certified arborist to determine if your ash tree is a suitable candidate for injection treatment because not all trees are. Things to consider include size, form, condition, and location of the tree.

Q: How do I tell if my ash tree is infested with EAB?

A: It is actually quite difficult to tell if an ash tree is hosting EAB until about 2-5 years after a female has first laid eggs on the bark and the newly hatched larvae have tunneled through the bark to feed on the phloem. There are, however, a few telltale signs.

The visible presence of the insect. EAB is a small, bright green beetle, and seeing one on an ash tree is a sure sign EAB is present. Mature adults generally feed onD-shaped holes the upper canopy of a tree, so they are not necessarily easy to spot. Watch for distinctive notching on the edge of the leaves that could indicate EAB is present.

D-shaped holes in the bark. Newly matured beetles emerge through D-shaped holes they have chewed in the bark. These are distinctive to EAB and evidence the infestation is well underway.

Patches of “blonding” of the bark. These paler patches Bark blonding revof bark are the result of woodpeckers and other insect feeders trying to get at the larvae. “Blonding” is often a sign that the tree is heavily infested.

As the infestation progresses, the impact on the health of the tree becomes more visible, with die-off in the canopy (thinning leaves) and shoots growing out of trunk as the tree struggles to survive.

Q: Where do I report suspected EAB on my property?

A: If you suspect you have EAB on trees on your property, you should:

  • Record the location of the tree
  • Record the signs and symptoms you have observed
  • If possible, collect an adult beetle specimen in a container and preserve it in a freezer

To report EAB in Manitoba:

  • Call the CFIA Emerald Ash Borer hotline at 1-866-463-6017
  • Call Manitoba Sustainable Development’s tree line at 204 945-7866 or send an email to treeline@gov.mb.ca
  • For the City of Winnipeg, call 311 or the CFIA hotline

Q: How long do I have before I have to do something about ash trees on my property?

A: Once EAB are confirmed in your area, you have only two options for ash trees on your property: treat them or remove them. The sooner you start an insecticide treatment, the better. However, you will need to keep treating the tree every two years. If you do nothing to your ash trees, they will eventually become infested and die. It is equally important to make a prompt decision on tree removal. Many arborists have a “no climb” policy that kicks in when 20-percent of an infected tree dies back. At this point, the tree has been dying at the roots as well, which dramatically escalates the risk of injury and property damage from falling branches or from the dying tree suddenly snapping off at the base. Delaying tree removal will increase the risk for arborists and tree-removal companies, and will increase the cost to the homeowner. Over the next ten or so years, the mortality rate for untreated ash trees in the City of Winnipeg will be 100-percent. There is an exception to the treat-or-remove options. If your property has its own wooded area, such as those along a riverbank, you do have the option of doing nothing at all. It means any ash trees growing there will eventually die and fall down, but if there is no threat of injury or damage to structures, you can simply let nature take its course and let the fallen trees decay naturally.

Q: Will the City of Winnipeg remove ash trees from my property or provide a subsidy so I can do it?

A: No, the City of Winnipeg is managing EAB infestations only on city boulevards, parks and public lands. The cost of ash tree treatments and ash tree removals on private property is the responsibility of the owner.

Q. I’ve noticed ash trees marked with a purple dot in my Winnipeg neighbourhood. What does that mean?

A. Ash trees marked with a purple dot have been scheduled for removal by the City of Winnipeg. All ash trees that are removed will be either chipped on site or disposed of at an approved disposal site to minimize the risk of the beetle being introduced into another area of the City. It is estimated that most ash trees on boulevards and in parks throughout the entire City will eventually be removed over a span of 10 years, if left untreated.

Q: I found D-holes in my lovely ash tree. Is it too late to start treatments?

A: Treatments are more successful if started before an infestation begins, but could still be effective if the infestation is not very advanced. The insecticide injected into the tree diffuses through the tissues, but EAB larvae feed on the tissue that moves the insecticide through the tree. If this tissue is significantly compromised, the effectiveness of the treatment is similarly compromised. If a tree is approaching or over 20-percent dead, it is generally too late to treat. It is best to consult with a certified arborist to determine if the tree can still be saved. The injection treatment can only be applied by a licensed pesticide applicator with a landscape/golf course specialization.

Q: I have a healthy ash tree in my yard. How can I save it?

A: The only viable option to save a healthy ash tree in an area where EAB is present is through an insecticide treatment via trunk injection, and you need to decide quickly if you’re going to undertake treatments. An EAB infestation can turn a healthy-looking tree into a dying tree in just two years. Talk to a certified arborist about the best options for your situation.

Q: How can I tell if an ash tree is still healthy enough to save?

A: Follow the 20-percent die-back rule. Stand back from the ash tree and look at the upper part of the tree for sparse leaves or dead and dying branches. If 20-percent or more is dying back, the tree is no longer healthy enough to be treated effectively. Look also for new shoots growing from the base of the tree. It is a strong indicator that the tree is already stressed and struggling to survive. The die-back and shoots might be caused by stressors other than EAB, but the tree is still not a good candidate for treatment. Another factor is the size of the tree. It makes more economic sense to replace small trees than to treat them. Trees that are greater than 20-25 centimetres in diameter at chest height are more suitable candidates for treatment. Consult with a certified arborist to determine the best option for you.

Q: What are the treatment options for healthy ash trees?

A: If a tree appears to be healthy, it can be treated with insecticides to stave off an EAB attack. There are four insecticides currently registered for use in Canada against EAB. Research shows that the most effective method of application is for insecticide to be injected directly into the tree under the bark, where it diffuses throughout the tree, killing EAB larvae feeding on the phloem and adults feeding on the leaves. Injections need to be repeated every two years and can only be done by a licensed pesticide applicator with a landscape/golf course specialization. Contact a certified arborist or tree-care company with a Manitoba Licensed Pesticide Applicator.

Q: How does an insecticide treatment for EAB work?

A: The insecticide is injected in the lower portion of the tree trunk through small holes drilled through the bark into the sapwood. The insecticide injected into the sapwood moves quickly though the tree t issues with the flow of water and nutrients. Within about 48 hours, the insecticide has translocated through the entire tree, including the leaves. The treatment needs to be continued approximately every two years.

Q: When is the best time for an insecticide treatment?

A: Product manufacturers suggest that the most effective time to for injection treatments is in late May to late June when the adult EAB beetles are emerging and trees are in leaf, but treatment can done through to August, or before the leaves change colour and drop as the trees start preparing to go dormant for the winter.

Q: How much does it cost to treat one ash tree?

A: The cost depends on the size of the tree. Treatment of an average mature tree can cost between $300 and $500 per tree, depending of the size of the tree, and treatment must be repeated every two years. It is recommended that you get a quotation from a local arborist or tree-care company with a Manitoba Licensed Pesticide Applicator. Naturally, the cost of treatment should be weighed against the value of retaining the tree (shade, beauty, etc.) and the cost of removing the tree and replacing it.

Q: Is there a safe insecticide I can use to treat my ash trees myself?

A: No. All products registered for EAB treatment by Health Canada are classified as commercial/restricted. They need to be applied by a licensed Manitoba pesticide applicator with a landscape/golf course specialization.

Q: If I want to cut down an ash tree on my property inside the Regulated Area, what do I do with the wood, branches and leaves?

A: The CFIA has establshed the City of Winnipeg as a Regulated Area for the Emerald Ash Borer. This means no ash material can leave the City. If you are in the City of Winnipeg and have hired a professional arborist or tree-care company, the company will dispose of the ash material for you. In many cases, the company will chip the wood on-site and haul the chips away. If you are doing the job yourself, take the ash tree material directly to the Brady Road Resource Management Facility (the Brady landfill), which is inside the regulated zone. To slow down the spread of EAB, do not move this wood to a new area, unless your are taking it to the Brady Landfill for disposal Please note that portions of the Perimeter Highway around Winnipeg are outside the Regulated Area. DO NOT leave the regulated zone on the way to the landfill.

Q: If I want to cut down an ash tree on my property outside the Regulated Area, what do I do with the wood, branches and leaves?

A: If the trees are outside the regulated zone (currently, all of the City of Winnipeg), there are no specific requirements for disposal of ash material. Once a tree is cut, it is a good opportunity to look for signs and symptoms of EAB. If any suspect material is seen, call the CFIA EAB hotline at 1-866-463-6017 or call Manitoba Sustainable Development’s tree line at 204 945-7866 or send an email to treeline@gov.mb.ca. Do not move this wood to a new area. EAB is difficult to detect, and wood being moved from one area to another puts all trees at risk.

Q: Can I burn a felled ash tree on my Winnipeg property?

A: You are not allowed to set an open-air fire to burn ash trees on site without a permit from the City of Winnipeg Fire Prevention Branch.

Q: Can I season ash wood cut on my Winnipeg property and burn it in my fire pit?

A: Yes, you can. Ash is a high-quality hardwood that burns beautifully when it is properly seasoned. After two years of seasoning, the wood will be dried and any EAB beetles in the wood will have emerged or died. While ash wood currently can be moved within the City of Winnipeg Regulated Area, it is advisable that you do not move ash firewood anywhere until it has been seasoned. A burning permit is not required by the City of Winnipeg for using ash firewood in approved fire pits and outdoor fireplaces. However, the wood from a newly felled ash tree will have a high water content, even if the tree is infested. Wood with a high moisture content (green wood) does not burn cleanly like properly seasoned wood. Burning green wood creates a smoky fire, which may create a smoke nuisance for your neighbours.

Q: I cut down an ash tree last year and it is sprouting this year. Will the sprouts become infested with EAB?

A: Ash trees at all stages are susceptible to an EAB infestation. It is advisable to kill the stump with a herbicide or have it removed by a stump-removal company.

Q: Can I take my seasoned ash firewood to the cottage?

A: No, you cannot move any firewood out of the Regulated Area unless it has been treated and you have written permission from CFIA. Permission depends of the time of year and the treatment of the wood.

Q: What types of materials are considered firewood?

A: Firewood is any untreated, raw solid wood material that is suitable for burning and is used for heat production. It often has bark attached and can be cut in pieces, logs, twigs, or in similar forms or lengths. Examples include mill-ends, stumps, branches, slabs, dockings, off-cuts, edging and dunnage. Wood material obtained from trimming, pruning or cutting down trees and shrubs is considered to be firewood if it will be used for heat production.

Q: I buy bagged and boxed firewood in Winnipeg from gas stations and supermarkets. Can I take it out to the cottage or to Bird’s Hill Park?

A: No, you cannot move firewood of any kind out of the Winnipeg Regulated Area unless you have written permission from CFIA. Firewood purchased outside the City of Winnipeg can be legally transported. It is always better to buy your firewood as close as possible to your end-use destination.

Q: I’m planning on selling my home in Winnipeg and have several very nice ash trees on the property. Will I take a hit on the selling price?

A: Real estate professionals say it is a matter of “buyer beware”, as there are no plans at this point to require the voluntary disclosure of the presence of ash trees on a property for sale. As the current homeowner, you have the choice of beginning treatment and transferring the responsibility for continuing treatment (roughly $300+ every two years for each tree) to the new homeowner. Ash trees left untreated will die within 2-10 years, depending on whether EAB is already present in your neighbourhood. The cost of removal (roughly $2,000+ per tree, depending on the location) becomes a liability that the new homeowner must deal with. It could affect the selling price, just as the need for a new roof would.

Q: Where do I find a tree-removal company for a quotation on taking down my ash trees, or for a quotation on treatments?

A: WAM does not endorse particular tree-removal companies, tree-care companies, and certified arborists. Check online for companies that specialize in tree removals and/or insecticide treatments. It’s a good idea to get two or three estimates in writing, and ask if the quotation includes all the work you would like them to perform, such as removal of all brush and wood, stump removal, etc. Tree-felling is dangerous work. Ask the company if it is insured for any injuries or damage, so that you as a homeowner are protected from liability. You can go to the Trees Winnipeg website for more tips on how to hire an arborist.