We've had an invasive species of some kind of termite move into this area over the last few years. 2 years ago my buddy lost almost his entire od crop to them. They eat out the center of the stems and branches, and they do it quick, within a few days the plant is dead, and as they move so quick, there's no symptoms on the plant until it's too late.
He's taken measures against them that worked really well last year, including adding diamectus earth (never spell that right, lol) to his holes and watering in Sierra Naturals Systemic treatment. A systemic treatment might help make the buds unpalpable to those worms too. He also uses the 7 dust