Mountain Pine Beetle Flight Time!! Beetles probably started flying early this month and may continue into September. For that reason, beetle infestation inspections will not be performed until late September. There is no value in performing inspections now, since trees may be attacked after the inspection giving property owners a false sense of safety. Please know that the very best time to perform inspections is in the fall. You may place your name in the queue for that time by requesting an inspection using the “Beetles” link on this site. There is also a great deal of detailed information about this epidemic at that location.