diseased leavesdiseased leaves Here are my avocado leaves from both sides. Can anyone please tell what kind of fungus or thing this is? It's causing all the leaves with those dark spots.

This is a 30 feet tall "don't know how many years old" avocado tree in a small town in the Gulf of Mexico. It's shaded by bigger mango trees in the back of my yard.

  • If this is an outdoor tree, where are you in the world?
    – Bamboo
    Commented Mar 15, 2018 at 23:28
  • Does look like an out door tree but whether indoor or outdoor this looks like an old mealy bug infestation with honeydew build up. Depends on the environment and size of an avocado tree for treatment but Graham's would work well for a large tree in the tropics.
    – stormy
    Commented Mar 16, 2018 at 2:48
  • Please merge your guest and registered accounts, which will allow you to edit, comment on any of your posts and accept an answer on your question. Thanks, and welcome to the site!
    – Niall C.
    Commented Mar 17, 2018 at 0:13

1 Answer 1


There looks to be a scale insect on the right hand leaf, and the top surface of the leaf looks infected with sooty mold. Treatment can be with a horticultural oil to smother the insects which secrete the sweet honeydew that gets infected with molds. Such insects include scale, aphids and mealy bugs. Look for ants in the latter case as ants farm these bugs for the honeydew and if you treat the ants nature might take care of the bugs.

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