Hi Alexander,

That is a pole borer (Neandra brunnea). They attack live trees when the sapwood becomes exposed and subject to high moisture. This often occurs at the base of the tree. They also attack dead wood, like utility poles that have rotted significantly (hence the name pole borer). This insect is managed by eliminating the risk factors leading to infestation (exposed sapwood, high moisture at base of tree). Insecticides are not effective for the pole borer.

Let me know if you have further questions.