I have already applied a different brand for a systemic application, but I was also looking for a contact spray because the borers are already in the limbs eating away. My Mesquite tree is weakened and stressed and I really want to save it. It was first noticed last year in October, many limbs were cut, now it seems they've returned earlier than expected (Because the systemic was supposed to last 12 months & it did not.
While Martins Tree an Shrub is labeled for flathead borers (including Bronze Birch, Alder Borers, and Emerald Ash Borers) it does not specifically list Pacific Flathead Borers.
We would recommend contacting your local Cooperative Extension Program for recommendations on treating this pest as according to this article HERE, the use of insecticides are advised against.
Answer last updated on: 08/25/2021