Many of us deal with whiteflies on indoor plants, but some varieties of these pests, particularly the silverleaf whitefly, can be problematic in the home garden. Here is what to look for with the silverleaf whitefly (Bemisia tabaci) and what to do about them.

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How Did Silverleaf Whiteflies Arrive Here?

It is a tale as old as time: This particular whitefly was introduced into the United States in the mid-1980s possibly from hitching a ride on ornamental plants. There are reports of clouds of whiteflies in California in the early 1990s. That is a sight no one wants to see! Today, they are found in California, Arizona, Texas, and Florida.

Although they only live for only a couple of weeks, the female lays up to 300 eggs, which hatch within a week. Because of this, they’ll produce over 20 generations during the season in these warm climates.

Besides their prolific numbers, one of the challenges with the silver leaf whitefly is it is not picky. They will target upwards of 500 different types of plants and are the vector of nearly 100 different viruses. This means that even when they don’t destroy the plants themselves, a subsequent infection, such as tomato yellow leaf curl virus, bean golden mosaic virus, cucurbit leaf crumple virus, among others, often kills the plant.

How to Identify Silverleaf Whiteflies

Like aphids and mealybugs, silverleaf whiteflies are sap-sucking insects that will drain the life out of a plant when its heavily infested. They’re one of a number of whitefly species, but this one is more problematic than most. While you’re most likely not going to take out a magnifying glass to examine the specifics of the whitefly, the silverleaf whitefly is about a millimeter long, yellowish-white, and its folded wings look like a little sail on its back.

You can typically tell that you have white flies because you see them. When you disturb a plant many times, they’ll flutter around the area. But you also want to check the plant itself because the adult whiteflies congregate on the underside of the leaves.

University of Florida: Edible Gardening Series

How to Handle the Situation

If you’re in an area where silverleaf whitefly is present, immediately dispose of infected plants because once the whiteflies infect the plant, you cannot save it. Place a plastic bag over it and tape or tie it at the base to trap as many whiteflies as possible. Then, pull out the plant or cut it off at the base, and disposed of it. Horticultural experts don’t recommend pesticides because they are not terribly effective and they promotes herbicide resistance.

The best solution is prevention. Using a silver-colored polyethylene mulch discourages silver leaf whiteflies, as well as thrips, aphids, and mealybugs. Break out the sticky traps and place them throughout the garden to capture as many as possible.

If you do find a few silverleaf whiteflies on a plant, treat it with Neem oil or insecticidal soap. You can also use a vacuum to remove them all together. But if you find the backside of a leaf covered in whiteflies, remove the entire plant.

In most gardens, whiteflies are annoying, but not a big problem. That is not the case in these southern states where this winged invader targets home and commercial gardens alike.