Spray a mixture of alcohol and water directly onto the mealy bugs if there are a large number of them. If only a few mealy bugs are seen, dip a cotton swab in alcohol and dab the insects to remove the waxy coating that protects them. Then spray the plant with a foliar spray or a root systemic insecticide. Repeat these steps at weekly intervals until no more mealy bugs are seen. Be sure the pesticide is designed for indoor plants and follow all pesticide directions carefully.
Scale are harder to find on a plant.
Many look like little bumps on the plant, and you may not realize they are not part of the plant itself. They tend to cluster together on twigs and leaf midveins. Infected plants may develop spotted leaves, branch dieback, and leaf drop. Many scale insects excrete a sticky liquid onto the plant surface, which forms an ideal place for mold to grow. Often this mold is black and sooty in appearance.