Observations from P. primuliflora cottony growths

[jimscott]

Once in awhile a P. primuliflora develops a cottony growth on a leaf. It never seems to have caused a problem and all I ever did was try to delicately remove it. This time I moved to under a shoplite and let it be. The growth is shrinking on its own. Now it's just a small patch.

What have others experienced or done?

 

[throckmoron]

Usually that sort of thing is a fungus or something growing on a gnat or tiny insect that was on the leaf--