Two Lined Chestnut borer is found in the oak trees of Minnesota. The name might seem confusing why they are found in oaks, but it is understandable why their food supply are the many varieties of oaks. The Two Lined Chestnut borer was originally found in chestnut oak trees. When they took out chestnut trees they adapted, and they are now working on all oak varieties. Oak trees are an easy transition as they are hard wooded just like chestnut trees.
These insects are very similar to the emerald ash borer. They are both flat headed borers. They make the same exit wounds when emerging out of a tree. The wound is shaped like a "D" like in the picture on the right hand side. Also similar to the emerald ash borer this insect lays eggs on the bark. The larvae are hatched and eat the trees veins that supply the tree with nutrients and water.
Timing
The larvae are most active when temperatures warm up in the spring. the adults emerge from oak trees around June to July. Two Lined Chestnut Borer can be found in almost every city in the Minneapolis metro area. Many of the larger oak trees are over 150 years old and are now in danger from this deadly insect.
Diagnosis
Since oak trees get oak wilt, as well, it is important to know the differences between these two harmful diseases. Learn more about the difference between the two problems on the fungus or insect page.
Two Lined Chestnut borer can be diagnosed if your oak tree has hanging brown leaves in clumps. It is usually too late once you see a bunch of holes around the trunk like the picture on the right shows. These insects, like many, start on smaller branches that are about an inch in diameter. This insect will not usually kill your tree in the first few years so you can see its progression through your tree and call Arbor Doctor to help you get rid of this pest.
Noticing the holes on little branches that fall to the ground can be very important in diagnosing problems with oak tree and many other trees. Also, noticing random die back, instead of sections, dying in your tree will help diagnose a problem. If you have an oak tree and you live in the Twin Cities it would be important to have someone check out your tree. Our initial consultation is free and we check every tree in your yard.
Treatment
Treatment for Two Lined Chestnut Borer is insecticide trunk injections. Arbor Doctor mainly uses the two year chemical, Emamectin Benzoate. This chemical is the same used to treat many other pests, such as Emerald Ash Borer. This treatment should be done in the spring for long lasting results.
Two-Lined Chestnut
Adult Two-lined chestnut borer
Decline from Two-lined chestnut borer
D-Shaped exit holes
