There is no spray for it. Ambrosia beetles bore small holes into stems and branches. They appear to be worse on young trees and as cherries leaf out. Once in the plant, it is too late to stop them. Spray stems to the point of run-off with Permethrin to slow their spread.
Yoshino cherries are beautiful, but temperamental.
However, many want to preserve their beauty for future generations to appreciate. Hopefully these tips will help you do this. For more information, call the Houston County Extension Service at 542-2020 with your questions. Remember we are busy at this time of year, so leave a complete message with your question, and be patient as we get back with you. You can also send e-mail .