Whiteflies are in the insect suborder, Sternorrhyncha. These insects are known for their rearward mouthparts, known as stylets; their “honeydew” secretion when feeding; and their life cycle progression from eggs to larvae to nymphs to adults. The whiteflies are distinct among these insects in that all of the adults have wings and can fly. Most flies of this species are white, though there are a few subspecies that are black. Learn what you can do about whiteflies on houseplants.
How to Identify Whiteflies on Houseplants
Some adult whiteflies can grow as big as 1-2 millimeters with 3-millimeter wingspans. Some of the flies remain small enough to evade detection and do not immediately damage plants, making it difficult to identify an infestation in the earliest stages. The adults have wings, but the nymphs are wingless crawlers and more translucent than white. That said, apart from their small size, the adults aren’t the best at hiding. These bugs can often be found on the tops of plants and the underside of leaves. When disturbed, they will take flight, making them even easier to spot.
Eventually, the leaves will turn yellow as more flies feed on the plant. The honeydew secretion may also attract ants and mold growth, which usually makes the plant unsalvageable. Whiteflies are easily confused with the white woolly aphid, another common houseplant pest in the same suborder. Fortunately, the same treatment and prevention is recommended for both types of pests. You do not need to be an entomologist to treat houseplants for whiteflies.
Whitefly Pest Control and Treatment
There are several treatment options you can take to control whiteflies. First, spray the plant with water and clean the leaves in a spot away from other plants to manually remove some of the flies. You can also put down sticky paper traps to capture a good portion of the adult fliers. A more aggressive and tricky way to remove these flies is with a handheld vacuum.
Next, you should continue to apply some type of insecticidal soap or oil to your plants to kill off any remaining larva and nymphs. You can also fight bugs with bugs by introducing ladybugs or lacewings to your plants. It can take close to a month for the whitefly to go from egg to mature adult. However, the adult female can ley between 200-400 eggs at a time. One generation of hatching whiteflies can be the difference between successful pest control and the permanent destruction of your plant.
How to Prevent Whiteflies on Houseplants
Whitefly prevention starts with strong, healthy plants and good houseplant care practices. We recommend continued use of preventative insecticides like neem oil and predatory bugs for houseplants that have suffered from these flies in the past. It’s also a good idea to closely inspect new and outdoor houseplants for pests before introducing them to areas with other cherished houseplants. Companion plants that repel whiteflies are sometimes suggested, but this is more effective if you’re struggling with whiteflies in your outdoor garden.
Cost-Benefit Analysis of Treating Houseplants for Whiteflies
If you’re sharp enough to catch whiteflies while they’re still nymph crawlers, then whitefly treatment has a good chance of saving your houseplant. If you notice leaves are turning yellow or you witness a small cloud of flies when the plant is disturbed, then you can try to cut out the affected growth and take aggressive treatment measures. A better plan may be to throw away the affected houseplant and take steps to ensure the flies do not spread to other plants.
Not sure if you’re dealing with whiteflies, aphids, or some other pest? Check out our full guide on identifying and treating different types of houseplant pests.