Locust Tree Damage in Michigan

Perry P

For the past two years I have had trunk injections performed by professionals on my 2 50 foot tall honey locust trees. I have seen where it is not recommended to do more than 2 consecutive years with injections. THis year the aphids are worse (May 26 2010). I used Bayer Medic Drench with Merit around both trees about 3 days ago. Should I have the trees professionally sprayed with insecticide also, or wait until until winter and maybe try a dormant oil. I am worried about the trees dying from this.

Perry P.

TreeSpecialist

The Merit® product should work without any additional spraying. It alsways works better when first mixed with a fertilizer. I've seen Merit® taken up in as little as 4 hours when mixed with fertilizer (bugs falling off the tree.)

Without fertilizer, Merit® can take several days to a week or more to move thorough the tree.

Abamectin (Abacide®) also works well and is a good alternative when injected properly. If you contact the local distributor of the products, you can purchase and do the injections yourself for very little money.

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Perry P

Tree Specialist: Thanks for the quick reply, however, my neighbor (who has the same type of trees) said the tree also has scales and he was told to apply an oil to remove them or do injections. According to the MERIT product I used it states it kills scales. Both trees are pretty heavily infested with the brown and white nodules which I assume are scales. I do not want to overmedicate the trees but would hate to lose them. I was wondering if I should injections also myself or hire a pro to spray the trees as they are 50 feet tall and even with a power washer I am not sure if I could reach the top. Thanks for the help.

TreeSpecialist

Merit®?either injected (Mauget®) or soil applied (with a fertilizer) would work best. Scales are very difficult to control. And after they are dead, they won't necessarily fall off the trees right away.

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Eric Frei

Trouble with using products like Merit to try and control scale is you will kill the good bugs that attack the scale.

I read that you guys are injecting and spraying trees for a few years and the problem is getting worse, likely you are killing all the good bugs in the area too. Maybe to break the cycle go do some homework on bio control and companion planting and lay off the insecticides.

Big Problem

Bio Control

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