We have 6 male Mulberry trees that have small bumps on some of the branches which are dying. These branches have very small leaves at the end. Our trees just started leafing out last week, mid March here in Kingman, AZ. At first we thought they were tiny bugs, but no, they are little about the size of a ladybug with sap in them (used gloves). They also drip sap everywhere. I have looked at every picture I could find and don't see anything like what we have. One other thing, the largest tree sits close to our septic (previous owner planted trees). My husband had trimmed the trees a few weeks ago, not cleaning the blade as we just found out we were supposed to. What in the world is it? Thank you.
Male Mulberry Tree Dying
Certified GKH Gardening Expert
Though the image is blurry, I do think that your tree has Galls on the branches.
Sometimes they can appear to be small insects, such as Scale.
There are about 1500 species of Gall producers that are mostly a type of mites or insects that feed and lay eggs.
They can also occur from a fungus, bacteria or virus.
In most cases they cause no issues with the tree. They can however weaken the tree and cause the decline of the tree.
You can do nothing and watch the tree or treat with chemicals.
An arborist will generally identify the cause of the Galls and apply specific treatment.
Keep the plant litter cleaned up from around the tree.