While an individual scale is small, the insects will cluster on leaves, stems and trunks. You can remove scale by carefully scrapping it off with your thumbnail or with a plastic scouring pad. The least toxic treatment, but most time-consuming, is a hard stream of water actually blasting the insects off the plant. This process must be repeated until scale is eradicated. Insecticidal soaps, pyrethrum and horticultural oils can be effective if applied while the insects are young and still in the crawling stage.
Mealybugs look like fuzzy cotton.
They distort and yellow foliage and stunt growth. Mealybugs, like aphids and scale, secrete a honeydew that in turn encourages the development of sooty mold on the plant. The female mealybug is a soft-bodied insect that's covered with a white, waxy fluff that provides protection from insecticides. Females lay eggs in white masses that hatch in about 10 days, and the young move around the plant, settle and feed. If an infestation is not severe, dip a cotton swab in rubbing alcohol and rub on the insects.