Question
I have small black growth on wax myrtle stems. Some are covered with this rough small protrudings. When I scrape it off with my fingernail it is wet and purplish when rubbed between my fingers. I have sprayed the branches with 50% malyathon at 3 tbls per gallon of water with some control results. After spraying and checking sometime later the growth is still there but seems to be dry when scraped and rubbed between fingers (not all treated branches are dry). Leaves on the infected branches have black mold also but it doesn't seem to cause them to die. Do you have any explanation for this.
I live in brevard county Florida.
  Thank you for your response.
  Don

Answer
Hi Don, I do not sell this plant but found some useful information for you.      Pests: Caterpillars, webworms, and mites may occasionally attack the foliage. Webworms common in some landscapes - prune
to remove infestation.
Diseases: Susceptible to several lethal diseases. Avoid any unnecessary pruning to help prevent this. Cankers including
Ptychogaster canker may form on old branches and trunks and kill them and the entire tree. Remove dead branches down far
enough to reach clear wood. Also, a lethal wilt disease caused by the fungus Fusarium oxysporum and Fusarium spp. has been
recently noted attacking Waxmyrtle plants in central and south Florida. Sphaeropsis gall infects plants in the east. Fungusspreads in wet weather during active growth. Branches die back. The only control is to prune to remove infected branches.
Inanotis heart rot decays the oldest xylem. Mushroom root rot can cause decline. This is a short lived tree due to these problems.  kathy