What is the emerald ash borer (EAB), and how is it relevant to the trees on my property?
The emerald ash borer is an invasive insect native to China, and was discovered in Michigan in 2002. Since then, it has spread to more than 30 states and 5 provinces and has killed millions of ash trees across the country. Once the beetle arrives in an area, it kills up to 99% of all ash trees within 8 – 10 years. In the context of Nova Scotia EAB was first detected in Bedford in 2018, placing us in a crucial window of time to act to save our ash trees.
How serious a threat is the emerald ash borer, and how do I know when to have my tree treated?
The EAB poses a very serious threat to all species of ash (Fraxinus spp.). Once infected, a tree will likely not live for more than three years, although it can die within as little as one year. The beetle larva kills the tree by feeding on its cambium tissue underneath the bark, cutting off nutrient transport to the rest of the tree. The bottom line is, without treatment ash trees will almost certainly die. Because of how aggressively the beetle spreads and how quickly it kills a tree, it is best to take a preventative approach and have your ash tree injected while it’s still healthy. However, trees can also be injected in the early phases of infection and be effectively treated against EAB.
How are ash trees treated for EAB?
To treat for EAB we use a systemic insecticide called TreeAzin, containing Azadirachtin at 5% solution as the active ingredient. This product is owned by the Canadian Forest Service and was developed in collaboration with BioForest, which holds its worldwide license. The product is injected directly into the base of the tree at multiple injection sites, using a battery-operated hand drill. Once administered into the conductive tissue, the insecticide moves upward with the flow of water and nutrients.
How safe is the product/TreeAzin?
Aspirin and caffeine are each approximately 10 times more toxic than TreeAzin. It is produced from neem tree (Azadiracta indica) seed extracts, and is listed by the Organic Materials Review Institute (OMRI) for organic use. Since the product is injected under the tree’s bark directly into the vascular tissue, all of active ingredient is administered directly to the target thereby increasing efficacy and eliminating the potential for adverse effects. After injection, TreeAzin degrades naturally and dissipates quickly in the tree upon reaching peak levels 48 hours after treatment.
Will the treatment injection sites cause damage to my tree?
Research has shown that healthy ash trees injected with TreeAzin using the EcoJect system showed little evidence of damage in just one year after treatment – new wood was produced over the injection sites with no evidence of pathogens and decay. Our certified pesticide applicators pay special attention to details that will ensure your tree recovers from the small injection sites, including but not limited to the number of injection sites, injection site placement, and drill bit condition to minimize cambium tissue damage.
How does the treatment work, how effective is it, and how long will it last?
It controls insect larvae feeding on the tree’s tissue (95% of feeding EAB larvae do not complete development and die), and also reduces beetle fertility and egg viability (<1% viable) when adult females feed on a tree’s foliage. With these multiple modes of action, the potential for pest resistance is dramatically reduced.
Treatment is effective against EAB for up to two years. As the infestation of EAB intensifies in HRM, our arborists may recommend treating two out of every three years (“aggressive strategy”) while the outbreak is in its peak. This is based on the BioForest manufacturer recommendation, from a Michigan State University study and historical Oakville, ON data and observations. Keep in mind, treatment injections are almost always less costly than tree removal.
Is TreeAzin effective against other insect pests?
Yes! In Canada, TreeAzin is registered by Health Canada’s Pest Management Regulatory Agency (PMRA) for the control of emerald ash borer, European elm scale, gypsy moth, tent caterpillars, spruce budworm, jack pine budworm, arborvitae leafminers, red elm bark weevil, birch leaf miner, and pine false webworm. If any of your trees (besides just ash trees) are showing signs of decline, this could be due to one of these insects. We can conduct a full health assessment of your tree to determine if TreeAzin might be the right solution.
I’d like to preserve the health of the trees on my property, but I’m not sure if I have any ash trees. What do I do?
Click here for tips about how to determine whether you have an ash tree on your property. Still unsure? Give us a call! Keep in mind that Mountain ash trees (Sorbus spp.) are not a true ash (Fraxinus spp.) and therefore will not be impacted by the EAB.
You can also refer to this document from the Canadian Food Inspection Agency (CFIA) to learn how to recognize the signs of EAB damage. New sightings of damage should be reported to www.inspection.gc.ca