Catch a few of the insects and have them identified. Unfortunately, often the indoor gardener first notices signs of plant stress, such as leaf drop, spots on the leaves, or a change in leaf color, without finding any insects. These symptoms may or may not indicate an insect problem. For the sake of brevity, we will assume you have caught and identified the insect that is causing your problem. While scale infections grow slowly, mealy bugs multiply rapidly.
Mealy bugs have small soft white or pink bodies.
In addition, they secrete a fluffy white wax which makes the plant leaf or stem look as if tiny bits of cotton are stuck to it. Infected leaves may be covered with small white spots. Leaves will fall off of the plant, black sooty mold may grow, and eventually the plant may die. In the meantime it is unsightly and a risk to healthy plants. Isolate any infected plant immediately.