Hi, I see that this case has been closed; however, I didn't hear back from you after I sent the other pictures. If they are cambium miners, what can I do about it?

Thank you

Frank 

I have never seen cambium miner in apple. However, if your trees are older, it is possible... have you seen larvae in the tree? How about sawdust?

Any more pictures might help. Thank you.

Hi again, Frank. I really think you do have borers in your tree. We have lots of different species, and I am not sure which of the species is causing your issue. The problem is that they are so hard to control because they are inside the wood of the tree. Our commercial growers spray pesticides on the trunk, but my guess is that you do not have a license to use materials that will kill them.... is there a way you can wrap your trunks in burlap? To provide a physical barrier to the beetles? This might work...

Nikki

I will try that. Thank you for your help.

Hello Frank. I am sorry to say that I am not sure trunk sprays will work. If your local company can do a trunk injection, that may work to kill insects that are already inside of your tree. How many trees have died as a result of this symptom? Do you see any dead limbs or leaves, and if you pull up trees, what do your roots look like? The trunks and bark from the pictures look very dried out. I am wondering if moisture or other pieces are at play in addition to your insect damage. Where are you located?

Nikki Rothwell

Hello. I think I have spoken to you in the past, and I am not sure of what is going on with your trees. One thing would be is to pull up a tree and take pictures of the roots and send them to me. I see those borers, but we do not usually see those pests kill a tree. I am wondering if something is going on below the ground that we cannot see. I am thinking voles... Please pull up a tree and take pictures. I think this will help us get to the bottom of this issue.

Nikki

Hello. Thank you for the new pictures. I think these trees are dying at the soil line. I think that this is winter damage. I see that you are up in Houghton, and I think this is the problem. How was your snow cover last winter or the winter before? Sometimes we can see trees go down with winter injury one to two years after the cold event. 

Did you take pictures of many trees or one?

Nikki

The bugs are minor, I believe. They are cambium borers, and we rarely see them damage trees enough to kill them. I suggested burlap to cover trunks to prevent them from boring because it is hard to get insecticide into the trunks--even commercial growers struggle with borers. My thing would be to give them foliar nitrogen applications as the leaves start to fall from the trees. They will take these nutrients back to the roots to store for the winter, and hopefully they will push better in the spring. Make sure the nitrogen source is for foliar use otherwise it will burn the tree, which is the last thing you need! Good luck. Let's hope for snow cover this winter.

Perhaps you can email me directly if you have further questions: <personal data hidden>