Treatment options for ash trees
If the tree appears to be healthy, there are insecticide options to prevent it from succumbing to emerald ash borer (EAB) attack. As of 2015, there are four insecticides registered in Canada for use for EAB, TreeAzin™, Confidor® 200SL, ACECAP®97 and IMA-jet. All of these are systemic insecticides that must be applied with trunk injections or implants by a trained applicator. Treatments must be repeated every year or two, depending on the insecticide, to maintain protection against EAB. Currently, there is little written about the effectiveness of Confidor 200SL and ACECAP®97. Early results for IMA-jet show reduction in EAB larvae and adults.
TreeAzin™ Systemic Insecticide is the most widely used at this time, and has shown good success in scientific trials, with limited environmental effects. TreeAzin is produced from extracts of neem tree seeds. It is injected directly into the tree and enters all of its tissues. It kills EAB larvae feeding on tree tissue by preventing the insect from developing. Treatment must be repeated every two years until the tree is no longer threatened by EAB. Injections are done by a licensed TreeAzin™ applicator.
TreeAzin™ treatment is more likely to be successful if started before the tree is infested with EAB or when infestation is at a low level. Trees that have EAB feeding damage may not respond, or may not respond as well, to treatment if their vascular tissue is compromised (this is the tissue that moves the insecticide through the tree). In some situations, trees already deteriorating from EAB infestation may respond to a more aggressive treatment program - discuss this with your treatment provider.