Tomatoes are a popular crop plant for home gardens. These plants are generally easy to care for and produce fruit that can be used in a wide range of culinary roles.
However, a few health concerns can devastate your tomato crop, especially whiteflies.
Immature and adult whiteflies are a small sap-drinking pest that tends to have yellow bodies and white wings that lay flush or slightly tented against their bodies.
There are many species of whitefly, and not all attack tomato plants.
But the ones that do, such as the sweet potato whitefly and greenhouse whitefly, will hide on the undersides of your tomato plant’s leaves.
Once there, these tiny pests will drink the plant juices of plants and vegetables, causing leaves to dehydrate and die.
At less than 1/10” inches long, whitefly species can be really hard to spot unless you’re actively looking for them.
Getting rid of an infestation when you find one can not only save your harvest, it might save the plant from further disease or infestations.
How To Get Rid Of Whiteflies On Tomatoes
There are three important phases to dealing with whiteflies: detection, elimination, and prevention.
Here’s everything you need to know to deal with a whitefly problem before they do much damage.
Checking For Whiteflies
Perhaps you’ve already discovered the infestation, but knowing the signs can help you spot the presence of whiteflies before finding the bugs themselves.
The most apparent of these signs is the yellowing and curling of the affected tomato leaves.
The leaves may also become stunted, wilt, and fall off prematurely.
As whiteflies are producers of honeydew, symptoms of sooty mold or the presents of ants on the plant are also good indicators.
Finally, whiteflies are known vectors for a number of tomato diseases, so a sudden infection can be a good indicator of whitefly activity.
To check for whiteflies, grab a magnifying glass and look at the undersides of any affected leaves.
Adult females lay eggs in clusters on the undersides of the leaves, taking about 10 days to hatch.
After hatching, their larvae won’t move but begin sucking the sap immediately.
You can also check the tops of plants or on stem ends.
If you see specks flying away when the leaf is disturbed, it’s likely whiteflies or a similar flying pest.
Whitefly nymphs are unique, as they resemble little white pods that often have multiple waxy filaments extending around them.
Once you’re sure whiteflies are on your tomato plants, it’s time to take action.
Eliminating A Whitefly Infestation
An infestation isn’t the end of the world, and the sooner you get rid of the whiteflies, tomato aphids, and mealybugs, the more likely your plants will recover in time to produce at least some of their normal harvest.
Natural predators are one good way to keep pest populations under control, and ladybugs are one of the most effective whitefly hunters, with parasitic wasps and lacewings also proving valuable allies.
You can order them online or introduce complementary plants, especially basil, dill, or parsley.
Control whiteflies using a neem foliar spray around dusk or dawn.
The timing is important, as neem dissipates in 45 minutes to 1 hour, so it will be gone before those natural predators or beneficial insects such as bees become active.
Examples of natural enemies of whiteflies include wasps, parasitized whiteflies, big-eyed bugs, lacewing larvae, and lady beetle larvae.
Other natural enemies for this pest include dragonflies and hummingbirds.
Be sure to spray all parts of the plant, especially the undersides of leaves and any split tomato cracks or crevasses the bugs may try to hide in.
Spray every other day for 14 days or until the infestation is gone, and you can safely harvest 24 hours after a treatment.
In a similar vein, neem oil soaks are a great option and work to protect your plant from not only pests but also many types of harmful microbes and fungi.
To use, simply pour 2 to 3 cups of the soil soak onto the soil, moving outwards to cover the estimated radius of the plant’s roots.
The plant will soak up the mixture, which becomes a systemic pesticide and can protect the plant from piercing or biting insects for up to 22 days.
Repeat the treatment every 14 to 21 days until the whiteflies are gone.
As with the foliar spray, you can harvest 24 hours after treatment. Another option is insecticidal soap or yellow sticky traps.
You can also make a dish soap solution. Just mix four tablespoons of liquid soap with one gallon of water.
Just apply the mixture with a spray bottle on the leaves of the affected tomato plants. Don’t forget to apply on the undersides of the plants where the whiteflies usually reside and hide.
When nothing else works in controlling the whitefly population, chemical insecticides are available, although these will often harm beneficial insects or even some plants and leave a toxic film on your tomatoes.
If you choose a chemical option, try to find one designed primarily for whiteflies – the fewer bugs it affects, the better – and ensure it won’t harm any other plants in your garden.
Prevention Methods Starts With Good Cultural Practices
As these pests like to hide, a lot of gardeners have found that plastic, foil, or reflective mulch can trick them into avoiding the area.
Weed thoroughly, remove any plant wastes that the whiteflies will try to breed in, then lay down a layer of the fake mulch, preferably when the plant is still young.
The fake mulch will protect the plant until its leaves block sunlight from being reflected back upwards.
Both of the neem remedies mentioned above may be applied as preventative, with the foliar spray being used every 14 days and the soaks being applied every 14 to 21 days.
Neem is one of the best prevention options, as it’s non-toxic to humans or pets (unless consumed in large quantities), won’t affect the flavor of your tomatoes, and can be used safely around beneficial insects and earthworms.
However, it has been known to be toxic to some aquatic life, so avoid using it near an inhabited water feature.