PEMBROKE — The Emerald Ash Borer (EAB) is an invasive, wood-eating beetle that is threatening Ontario’s ash trees. The insect was first found in North America in 2002 and was likely imported from Asia through improperly treated wood packaging material. It has spread rapidly, mostly through the movement of firewood or other infested ash wood material. Discovered in Ottawa in 2008, the EAB has had a major impact on street trees and parks.
Emerald Ash Borer was first found in Renfrew County (Arnprior) in the spring of 2013, and in the Renfrew/Horton area in 2015. This year, the presence of the insect was confirmed in Cobden. The whole of Renfrew County is already in the Canadian Food Inspection Agency’s (CFIA) regulated area for Emerald Ash Borer, which means that movement of firewood or other contaminated materials is not prohibited, as long as it stays within the regulated area. However, to slow the spread of this insect that has not yet reached most of Renfrew County, it is recommended to not move firewood and dispose of infested ash in a manner that prohibits further development and spread of larvae that might still be inside (e.g chipping to <2.5cm in any direction on site, or burning on site). The greatest issues facing Renfrew County as a result of EAB are the loss of ash street trees, and the potential impact to unique ash forest stands (e.g. black ash swales). Emerald Ash Borer only affects true ash (Fraxinus) species. Once infested with EAB, trees typically die within 2-3 years. Early detection is difficult and by the time damage is obvious, the tree is usually heavily infested. Similar signs and symptoms can be caused by other pests, drought or drainage issues. Obvious signs of EAB infestation include S-shaped galleries created by larva feeding between the bark and sapwood of the tree and D-shaped exit holes (3.5-4mm wide) created by adults at time of emergence from the tree. Many more signs and symptoms may present themselves and you can learn more about identifying them online through many resources, including a document produced by the Canadian Forest Service http://cfs.nrcan.gc.ca/pubwarehouse/pdfs/26856.pdf. If you want to help slow the spread of Emerald Ash Borer, here are 5 things you can do: 1) Don’t move firewood. This is a good practice in general, since a number of serious forest pests can be housed in dry or rotting wood. It is especially important not to bring any unused firewood home with you if you have been camping outside of the County. 2) Don’t plant ash trees. Spread into your community is likely and the continued planting of ash trees will result in a loss of investment. Plant another native tree species well-suited to your site. 3) Explore your treatment options. If you have an ash tree on your property that you can’t bear the thought of losing, there is a preventative treatment approved for use in Canada that has proven effective in protecting against EAB (www.bioforest.ca). 4) Plant a new tree. Keep in mind that treatment may not be a long-term solution if you don’t plan to continue it over time – retreatment is required every 2 years. Another option is to plant a new tree in the same area as your ash tree to lessen the visual impact if the tree becomes infected with EAB and needs to be removed. Your best bet is to plant now to give the new tree time to grow before the potential removal of your ash, and to choose a native tree species well-suited to your site. 5) Be kind to your ash. Although the insects are known to attack healthy and unhealthy specimens, there is hope that some trees may be genetically resistant. Keep your ash trees healthy by avoiding damage to the tree above and below ground, being careful to avoid compaction from heavy vehicle traffic or construction within the dripline of the tree. Pre-emptive removal of ash on your property is NOT recommended. For general information and links to more resources, please visit the County of Renfrew website at: http://www.countyofrenfrew.on.ca/departments/development-and-property/forestry-and-gis/forestry/eab/
