Question
I have a Mimosa tree that is about 12 years old.  Just recently I noticed it is suffering from mimosa wilt where the leaves are turning yellow and falling off.  There is also sap oozing out of small holes in the bark, usually on the underneath side of the branches.  I lifted a piece of bark off one of the branches and noticed there are small bugs that look like mites.  Are these bugs what may be killing my tree and will they spread to my Bottle Brush Trees and African Sumac Trees?  Thanks, Ken

Answer
The mimosa wilt is what is killing your mimosa. The insects are just there to feed on the fungi growing under the dead bark. No the wilt nor the insects will get on the other trees or bushes. Insects and diseases are generally host specific meaning they attack one or a couple of related host plants and will not bother other species of plants.

A balanced fertilizer (10-10-10) may help alleviate symptoms in infected trees; never use high-nitrogen fertilizers. Use 1 lb per inch of trunk diameter scattered around the tree and watered in good. Infected trees should be watered frequently to decrease wilt symptoms, and dead branches should be removed and burned.

Because Fusarium is a vascular wilt pathogen, surface-applied fungicides are not effective. Even with systemic fungicides, chemical control of Fusarium wilt is not practical when treating established trees. The most economical control is to plant resistant cultivars of trees and shrubs.