What may have happened is the tree may have gone unwatered for a long period of time, maybe neglect for 2 or 3 years. That can kill back parts of the tree, and it may never be able to fully recover again. If that is the case, the best thing you can do is try to give it proper care now. Make sure you keep it watered during the summer. Can you tell us where this tree is?

Darn it when things aren't as we'd like! But, it's not a stupid plant. It needs love, too. I would consider cutting it back. Could turn out to be your favorite plant ever. Now, time to head on over to some of the plumeria seller websites and pick out one you'd like to have. I may just do the same!

Can anyone help diagnose and treat my tall, ten-year-old plumeria trees? The main trunk and branches have deep wounds that appear to start as dry, splitting bark. My beloved plumeria began as two small sticks , which sprouted for me and faithfully bloom year after year. I keep them indoors from mid-Sept. through late May because oof Minnesota's terrible winters. I treat them lovingly all winter long as they fight spider mites and dryness. Usually they thrive once they are taken outdoors to fresh air and saunshine. BUT not this year - they have very tiny leaves and wounds all over their branches. THANK YOU.

That appears to be thrip or mite damage. The plants should recover from it rather quickly. It sounds like you figured it out on your own but just didn't know the best approach to get rid of the crawling "brown thingies." Look for a Neem oil or a 3 in 1 type product to treat all surfaces of the plant including undersides of leaves. edit: forgot to add... this time of year you should expect leaves to yellow and fall off as the plant prepares for a dormancy period. Generally speaking the oldest leaves (or sometimes the most damaged leaves) yellow first.