Pests frequently enter a home through a seemingly innocent decorative staple: houseplants. Various insects and less noticeable mites can infest plants before they are even brought back from the store. Spotting the pests is the first step to exterminating them.
An infestation can damage the appearance and health of the plant, and will occasionally kill them. Regardless of side effects, the pests pose a bothersome problem.
Whiteflies look slightly like gnats covered in a waxy white substance. Adults will have wings, and are typically very small. They’re not difficult to spot on darker leaves, as their light coloring contrasts with the plant. These pests are most damaging at their younger stage, as that is when they consume the plant. Whiteflies inhabit the undersides of leaves, so regularly check your plants for the small white insects.
Mealybugs are easily visible at about three-sixteenths of an inch long. They can resemble mildew, but upon closer inspection will be moving. Like whiteflies, they are lighter in color and stick to the undersides of leaves. They also populate near the stem and at the base of the plant, so be aware of anything that looks like mildew on an indoor plant.
Thrips are tiny and darker than mealybugs and whiteflies, which makes them harder to spot. They hop rather than fly, so identifying thrips can be done after examining a plant for more than a few seconds under a magnifying glass. The mites eat flowers in addition to leaves and stems, so unusual streakiness on flower petals could indicate a thrip infestation.
Aphids are usually found on household plants, but infestations can be found in dense wooded areas outdoors as well. Indoor aphids range in color from green, black, brown, gray, yellow, red or purple. A study done by the University of Minnesota suggests looking for clusters of aphids beneath flower buds and on petals.
A fact sheet from Colorodo State University recommends keeping plants in a separate area of the house, away from already-established plants for a few weeks before moving them to a permanent location. Scale insects (whiteflies and mealybugs) are present on most houseplants that have been recently purchased. Most mites can be removed easily by running the plant under water on moderate pressure, while whiteflies and other airborne insects can sometimes be tamed with sticky traps.