Asked November 11, 2020, 9:23 AM EST
Wayne County Michigan
I’m sorry to hear about your honey Locust. The honey locust borer usually attacks trees that have been stressed, usually due to drought. There were several periods of no rain during the past summer which may have contributed to the problem. Also, trees that have been improperly pruned or been damaged by root pruning or disease and other environmental causes may also exhibit stress.
Honey locust borers are metallic or long-horned beetles that spend larval stages tunneling under the bark of the trees. Evidence of borer activity usually includes weeping at wounds and small circular exit holes made by adults as they emerge from the trunk.
Read the following bulletin from the Morton Arboretum to learn more about the borer. https://www.mortonarb.org/trees-plants/tree-and-plant-advice/help-pests/borers
The best way of reducing problems from honey locust borer involves proper watering, tree care and wound prevention. Supplemental chemical controls would involve protecting the trunk with an insecticide during the period of egg-laying and egg hatching. Alternately, applications of insecticides as a soil drench could protect neighboring trees that have not been attacked by the borer.
For advice on what pesticides to use to prevent the spread of the borer, you can consult the MSU Plant and Pest Diagnostic Lab. Go to: https://www.canr.msu.edu/pestid/ to learn how.
Because these are mature trees and difficult for you to treat, you could also contact a certified arborist. Go to: www.treesaregood.org , the website of the International Society of Arboriculture to find an arborist in your area.
Good luck with your trees. Thank you for contacting Ask Extension.
Sent from my iPhone
On Nov 12, 2020, at 12:06 PM, Ask Extension wrote:
You are welcome.