The scale insect can be a big problem for houseplants because after it attacks, it literally sucks the life out of your plant. Several species of scale exist: this insect is tiny and can range in color from pink to black. It begins life as a soft-bodied adolescent, which you can control with a soap spray. But when it matures it becomes armored, which makes control more difficult. It's important to begin your control of scale insects as soon as you notice them because they can decimate a plant if you don't catch them in time.
Controlling Scale on Houseplants
Watch for ants, which "farm" insects such as scale and aphids. If you begin to see any ants, look closely for any tiny "bumps" that could be young scale insects. To prevent ants from climbing up into your plant, spread a layer of a product called Tanglefoot around the main stalk or trunk of your plant.
Spray your plant with insecticidal soap if the scale appear to be the soft-bodied juveniles. You can purchase this type of soap at your local nursery or make your own. (See Tips.)
Mix one tablespoon of canola oil into a 1-quart spray bottle and then fill with insecticidal soap. This will smother and kill the older, armored insects.
Use an ultra-fine oil that you can purchase at your nursery if the other controls don't work. This type of oil is highly refined and when you use it, it coats the insects and their eggs, preventing respiration and other bodily functions.
Hand pick and squash as many scale insects as you can find. Continue with this practice until you find no more insects on your plant.