Tropical Zone Gardening: name this mango disease, 1 by happyisland

happyisland wrote:
Hey tropical party people,

My valencia pride mango tree is now about 12 feet tall and seemingly doing very well. On closer inspection though, large sections of the foliage are covered with little black dots (see the attached picture of a representative leaf). What is this disease, and how can I treat it? Googling didn't turn up an answer, so I'm turning to you, my worldwide tropical gardening experts. Thanks!