Gardening Articles: Health :: Houseplants
What's Bugging Your Houseplants? (page 2 of 4)
by Susan Littlefield
Aphids are pear-shaped, soft-bodied insects that feed by sucking, usually on the newest growth, and are often found in large numbers. Sometimes you'll notice the sticky ″honeydew″ they excrete, which turns a dark sooty color when mold grows in it. Because aphids are generally found clustered on the tender new growth of plants, start by pinching off and destroying these heavily infested parts of the plant. The kitchen sink sprayer will often take care of a mild infestation. Insecticidal soap sprays are effective for bigger pest populations.
Mealybugs look like flattened, oval, cottony masses on the undersides of leaves or tucked into the crevices where leaf stalks meet stems. They are covered with a white, powdery wax that looks like finely ground meal; hence their name. This waxy material may extend out from their bodies in lacy filaments. Mealybugs feed by sucking, weakening plants and causing yellowing leaves, distorted growth and dropping foliage. Like aphids, they may also secrete sticky ″honeydew.″ As many as 600 eggs are laid in a mass of cottony wax, so it's easy to see how a population explosion can happen quickly. While the adult insects may appear immobile, they crawl slowly and can spread from plant to plant, especially when leaves touch. Eggs hatch out onto mobile crawlers. This is the stage that is most vulnerable to insecticide sprays, because the newly hatched crawlers lack a protective waxy coating.
Use a cotton swab dipped in rubbing alcohol to remove individual insects and egg masses, repeating weekly until all of the pests are gone. Or you can dislodge mealybugs by washing plants with a soft brush or cloth dipped in a solution of two teaspoons mild dish detergent in a gallon of warm water. If your plant is heavily infested, you can spray insecticidal soap or a mixture of one part rubbing alcohol to nine parts water directly on the mealybugs. Be sure to test these treatments on a small section of the plant before treating the entire plant since the foliage of some plants may be sensitive them. You'll need to make repeat applications according to label instructions to catch insects at a susceptible stage in their life cycle. It's probably best to discard severely infested plants.