Hello, can anyone tell me what I need to do to keep bugs off my little mango plant? I saw a white hopper on it this morning. This afternoon I looked at underside of leaf and saw a white powdery substance. I gently wiped it off with my finger knowing it wasn't suppose to be there (hope it wasn't a mistake). The plants are outside in pots. I also saw the world's smallest aphid. At least I think that's what it was..not sure it was sooooo small, could hardly see it. It was kind of brownish-reddish in color. Please help. Do I need to spray with with something?