Emerald Ash Borer - What to do

by Dave Scharfenberger, Board-Certified Master Arborist WI-0131B

Recently a lot of attention has been focused on emerald ash borer (EAB). This Asian invader looks like it could be our next big tree problem. Over six million ash trees have been killed in the Detroit area. At waysides north of Detroit, vehicles have been inspected for firewood. Of the vehicles with ash firewood, 80% have active EAB! This is a very discouraging statistic that concerns us about the ability to contain this significant insect.

No EAB has been found in Wisconsin!

Yet, everywhere it has been found so far, entomologists feel it has been present for two years or longer before it was discovered. Given these facts, we are letting our clients know that if you have high value, important ash trees, you should consider treating them with Merit this fall to start protecting them from EAB. This treatment will need to be done every year for continuing protection.

Merit is labeled for boring insects and works very well as a deterrent to infestations (as opposed to a cure). While Merit does not have a long track record with EAB, tests are showing an 80 to 85% success rate. The biggest problem for a few people might be the early control measures that are used by the government. These early control measures (used for a satellite infestation) involve cutting all ash trees down within a half mile of an infested tree, even if trees within the satellite area are being treated. Once an area is considered infested, Merit treated trees will be spared from removal. While the chances of a satellite site are fairly small, it is something that needs to be considered before a treatment decision is made.

If you have ash trees that are important in your landscape and want to take a proactive step to help protect them from emerald ash borer, begin Merit treatments. No one knows when EAB will arrive in Wisconsin but with Wachtel’s help you can be ready!

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