I'm hoping this looks familiar to someone. Last Thursday I noticed it looked like something burrowed into the stem of my young avocado tree. There was a hole with a lot of white powder around it. We had a lot of rain yesterday and when I went to look at my tree today the white powder wasn't around the hole anymore but a bit farther down the stem. It looks like there's a lot of powder inside the hole though.
Did some kind of bug do this? Should I be really worried it's going to keep burrowing in the tree and kill my avocado? I bought the tree last summer from Home Depot and have been trying really hard to keep it alive with our poor draining soil and the sun burn it had last year. Now it's finally growing again after being stagnant for 6 months...