I have observed some kind of slime on some of my plants, it looks like "spit", is it serious? (Dominica 62)
This is without a doubt the frothy leafhopper.
It is a parasite, often harmless, which does not need to be treated with conventional insecticides, even organic.
First, you just need to clean the plant with a water jet in order to get as much of this slime out as possible, only if you notice that the plant is in pain.
Otherwise, let nature take its course.
If you still need to treat, it is best to choose an organic method of insect treatment.