Identify pest

Asked October 25, 2018, 4:57 AM EDT

this pest has killed a lot of my small apple trees. It bores in at the base making it like honeycomb and the tree dies. This is follow up from yesterday when I didn't include a pic.
Also, please how to eradicate. I know of no one else with this problem.

Delta County Michigan

1 Response

The picture is a bit fuzzy but it looks like you have a roundheaded apple borer. As you have seen this insect can cause considerable damage to the base of apple trees.

If you find areas with strings of sawdust-like frass coming out of holes, it may have a borer inside. Poke a stiff wire into the hole to kill the borer.

Use a white latex paint to coat the bottom 2 feet of the trunk. This is somewhat repellent to borers.

Remove weeds around the base of the trunk.

Commercial growers provide some protection by spraying the lower trunk area once per year with insecticide such as Assail (active ingredient: acetamiprid). This will not help a tree that is already infested. It may be difficult to find this insecticide in a backyard gardener sized package. Most of the common insecticides used by backyard gardeners are too weak to have much protection from trunk borers.