My mature avocado tree is dropping all it's leaves

[Rob Tucker]

The leaves that are down are brown from the stem following the veins in the leaf. It's an old tree. If beetles are getting it I will just have to watch it go. I did find that a banyon was rooting on it and cut that back.

Thanks for your input everyone. Since no one else seems to have the problem I am resigned to watch it and just see what happens. There are massive buds on it which look fine.