Indoor plants can be very rewarding and most of them require minimum care. Nonetheless, they do need to be checked regularly, as sometimes, through no fault of your own, they can suffer from various diseases or pests. Whiteflies are among the most common pests that attack indoor plants.
These annoying little insects can affect a wide variety of ornamental plants, but they can also attack certain greenhouse-grown vegetables such as tomatoes, eggplants, plants from the cabbage family, or sweet potatoes. While these pests don’t thrive outdoors, if you move indoor plants outside, the infestation can survive a season, especially in warmer areas.
Whiteflies are generally easy to notice, as the insects can be seen flying around your plants, but it can be hard to notice them in the early stages of the infestation. Moreover, once you notice them, they can be very difficult to remove. Keep on reading to learn how to identify these pests, how they affect your plants, and what you can do to get rid of them and prevent future infestations.
What Are Whiteflies
- Also known as citrus whiteflies or greenhouse whiteflies, these pests belong to the Aleyrodidae family of insects.
- These tiny insects are no larger than a tenth of an inch and they have a triangular shape, a tiny yellow body, and white wings. They are related to aphids and they use their piercing mouths to suck the juices in plant leaves. They usually prefer plants with softer leaves and they will thrive on fresher leaves or the juicy vines of the leaves.
- These insects lay their eggs in late spring. A female can produce up to 400 eggs, which are laid in concentrical patterns on the undersides of the leaves, usually preferring a plant’s upper leaves.
- It takes up to 10 days for the eggs to hatch into nymphs. The nymphs crawl and latch onto a preferred location on the leaf where they will stay and feed until they are ready to emerge as adults. Nymphs can be hard to identify because they don’t move and they can sometimes blend their color with the leaves. It takes about a week for nymph larvae to emerge as adults.
Symptoms of Whitefly Infestation
Adult whiteflies are very easy to notice as they tend to fly around whenever you disrupt the leaves of your plants. They usually stick to the undersides of the leaves, where they lay their eggs, so you might not notice them by simply looking at the plants. It is recommended to inspect all your plants regularly, but if you have a lot of plants, you may not always find the time to properly inspect all of them. Nonetheless, try to at least move the leaves around each time you water a plant. Whiteflies are active during the day when they feed, so they will definitely fly around if you shake the leaves slightly.
When dealing with infected plants, you may also notice a white waxy substance on the leaves and the fronds as well as a sugary substance. This sugary substance is called honeydew and it is produced by most insects that feed on plant leaves. The leaves of infected plants may also exhibit a dark sooty mold. This mold is a fungal disease caused by honeydew. Typically, whiteflies don’t kill healthy plants, but they can cause a lot of damage. Primarily, these pests can inhibit photosynthesis which in turn will lead to yellow or wilted leaves, stunted growth, and fallen leaves.
How to Prevent a Whiteflies Infestation
It is always easier to prevent a big-scale infestation than to treat it so here are a few simple steps that you can take to prevent whiteflies from establishing a home on your indoor plants.
- Be careful with new plants – Whenever you bring a new plant home, make sure to inspect it properly for signs of pests or diseases. If your space allows it, choose an isolated place for your new plant and keep it under observation for a couple of weeks before placing it near other plants in your home. While it is less likely for whiteflies to reside in soil, it doesn’t hurt if you also keep new soil in isolation before using it as a medium for healthy plants.
- Do regular maintenance on your plants – A healthy plant that grows in a good environment is less likely to be affected by pests and diseases. So make sure your plants grow in an environment with proper humidity and take the time to inspect, prune, and care for your plants regularly.
- Choose your fertilizers wisely – Pests thrive when they feed on healthy plants but certain substances make a plant even tastier to different pests. For example, a high content of nitrogen in plant tissue will encourage these pests to grow and reproduce faster. As such, try to avoid fertilizers that are too rich in nitrogen.
- Avoid chemical insecticides – For greenhouse plants, it helps if your environment is insecticide-free, as natural predators such as spiders and ladybugs will naturally keep whiteflies at bay.
- Use aluminum reflective mulch – This is a great solution for greenhouse crops as it prevents whiteflies from finding host plants.
How to Treat a Whitefly Infestation
There is no magic solution to treating a whitefly infestation, but there are some methods that yield great results, especially if you apply them consistently. There is no need to resort to pesticides, at least not before you try some organic removal methods. For the best results, apply these treatments in the morning or the evening, when the whiteflies are less active and more vulnerable.
Isolate the infested plants
The first thing that you need to do when dealing with a whiteflies infestation is to isolate the affected plants to prevent the pests from migrating to nearby plants that are healthy.
Blast the pests off with water
Depending on the size of the affected plants, you can use a hose or a spray bottle to blast the tiny insects from your plants. Adult flies will scatter more quickly, but you will need a little pressure to dislodge the nymphs. When dealing with potted plants, it helps if you do the treatment outdoors, so that the insects that are scattered don’t get the chance to find their way back to their host.
Use yellow sticky traps
You can find commercial sticky plant traps at most garden shops and they work for all insects that feed on plants. Yellow looks like foliage to insects so they will immediately be attracted to the traps. You can also use some basic cards that you can coat with petroleum jelly. This method is very effective for adult flies, but you will still have to use another treatment for the nymphs that are lodged onto the leaves. Sticky cards are great for greenhouse plants that can’t be moved during the treatment.
Vacuum the flies
If you own a handheld vacuum with a low suction setting, you can try using it on the leaves of infected plants. Try to be as thorough as possible, and only repeat this procedure once every few days, to avoid stressing the plants and causing unnecessary damage.
Make use of aromatic plants
Not only do plant pests not eat aromatic plants but strong scents repel them. As such, it doesn’t hurt if you add some fragrant plants to your garden to drive away pests. For the best results use mint, parsley, or cilantro.
Use an insecticidal spray
As we already mentioned, it is best to avoid insecticides as much as possible, so that you don’t harm good insects that protect your plants. Nonetheless, if all other methods fail, you can try an insecticidal spray. Just make sure to only spray the undersides of the plants, so that you don’t inhibit photosynthesis. Moreover, there is no need to spray the upper side of the leaves, since the whiteflies don’t stay there. There are several solutions to choose from:
- Garlic spray – This is a non-invasive treatment, but the pungent smell can be very uncomfortable so this treatment is only recommended for greenhouses or outdoor plants.
- Neem oil spray – This can be used on any plant and it will affect whiteflies in all life stages. It can also be used to prevent pest infestations. For the best results, mix one teaspoon of neem oil with one teaspoon of dish soap. Dissolve the mixture in one liter of water and reapply every few days. Some plants can be more sensitive, so test the mixture first. If it causes leaf burn, add more water to dissolve the solution.
- Vinegar spray – This method can also be used on a variety of pests. Mix 1/8 cup white vinegar with a cup of water. Test the solution first and dilute it if needed.
- Soap spray – Mix a teaspoon of basic dish soap with a liter of water and apply it on the undersides of the leaves. Allow the mixture a few hours to kill the pests and then rinse the plants. Repeat the process every couple of days until you rid your plants are completely pest-free.
Whiteflies are not the most dangerous parasites but they can be quite annoying. Let us know if you’ve tried any of the whiteflies removal techniques mentioned in the article and which one was the most effective!