What Bug Is On My House Plant?
Signs of Insects on House Plants
Learning how to tell what bugs are on your house plant is important, because once you spot their signs, it's almost too late to do anything about it and save your favorite plant. Indoor gardeners need to know gardening techniques for their house plants to prevent insect infestations just as outdoor gardeners need to know telltale signs, too.
Does this sound familiar? One day, you stroll into the living room and notice what looks like a bit of white fluff on your spider plant. Hmmn, you think to yourself, I should dust more. A few days later, the plant is drooping, the leaves turning brown. You water it, hoping it just needs a boost. It doesn't help. You give it a shot of fertilizer and it looks even worse. Within days or weeks, the white stuff has spread and your plant is dying.
Congratulations. You have a dead plant, and a healthy colony of mealy bugs.
Most insects that plague house plants leave a calling card rather than ring the front doorbell. In other words, they give signs of their presence through changes in the appearance of the plant or unusual new colors and textures on the plant surface rather than being visible to the naked eye. Many insects pests are even so tiny that you need a magnifying lens to see and identify them properly.
If you have house plants, you must check them every time you water them for signs of insects and diseases. It's not hard to do, and an ounce of prevention is worth a pound of cure. Here are the telltale signs of insects on houseplants, and what to do about several common pests.
One of the easiest to recognize signs of insects on house plants is actually seeing flying insects on or near your plants. Sometimes the insects appear to be tiny gnats hovering near the plant. Sometimes you pick up a plant and dislodge a small cloud of insects who quickly settle back on the leaves. Any of these are signs that you should inspect your house plants more closely and investigate further.
All treatment options below are suggestions only. Please use care and caution and when in doubt, speak to a professional at your local nursery or garden center. Any pesticide use or application is at the reader's own discretion and you must follow the label directions.
- White Flies - white flies are, as their name implies, small white flying insects. They hide on the bottom of the leaves. Shaking or moving the plant can dislodge them. Many homeowners bring them indoors when moving plants from outside to indoors during the fall months. White flies are common on tomatoes and many garden plants and can easily transfer to house plants vacationing outdoors. One way to prevent infestation among your house plants is to thoroughly rinse house plants before bring them back indoors, or using an insecticidal soap as a preventative measure. Insecticidal soap usually removes them adequately.
- Thrips - Thrips are tiny winged insects that feed on flowers and leaves. One way to tell if your plant has thrips is by the flowers. Thrips burrowing into flowers distort and disfigure them. Leaves will get splotchy, with yellow sections, when a thrips infestation is present. The best way to identify thrips is to use a sticky card, either one purchased at the garden center or one made at home, to trap the flying insects so that you can look at them under a magnifying glass and compare them to pictures in books to be sure you have thrips. Usually a systemic pesticide is necessary to get rid of thrips.
- Fungus gnats - Adult fungus gnats fly, but the larvae burrow into the house plant's pot and gnaw at the roots, causing extensive damage. Sliced potatoes placed cut-side down on the soil surface lure the gnats away from plant roots and into the potato. Every few days, remove the slice of potato and throw it out in an outside garbage pail away from other plants and replace it with a new slice of potato. You will need to keep doing this for several days or weeks to get all the fungus gnats out of the plant, since there will be many and they will be at different stages of their lifecycle by the time you notice them. A conventional insecticide soil drench is also effective; read the label to choose one suitable for your plants and to use it carefully. You should also repot your house plant at the earliest opportunity and throw away the infested soil. Allowing plants to go dry between watering times cuts down on these insects, since they feed on fungus growing in the soil and near the roots, and fungus needs moisture to proliferate.
How to Make a Sticky Card
Sticky cards are yellow or blue cards with a sticky film over them that you place in a house plant pot. Insects are attracted to the color, fly into it, and get stuck. You can then throw out the card or look at the trapped bugs under a magnifying glass for identification purposes. Most garden centers sell the yellow cards, as the majority of bugs are attracted to the color yellow. A few, however, like blue. You can make your own using a colored index card. Simply smear a thin film of petroleum jelly on the center of the card, covering most of it but leaving the edges of the card dry to make it easier to handle. Then using a plant stake or bamboo stake and a clothespin or clip of some kind, attach the card to the stake, place the stake in the pot, and voila - instant sticky card.
Visual Signs of Insects on House Plants
Remember that white cotton ball description at the start of this article? That's one sign of mealy bugs. They love cracks and crevices in the plants, and colonize them, making what appears to our eyes what looks like a white puffball. They're easy to remove. Dip a cotton swab in rubbing alcohol and use it to wipe off the white puffy stuff. You may need a conventional systemic insecticide to get rid of them all or multiple treatments, as they can burrow down deep inside the plant.
Another sign of an insect infestation on house plants is seeing what looks like thin, spidery webs. Unfortunately, that's a sign of the dreaded spider mites. Spider mites are extremely difficult to remove. It's probably best to remove the plant and discard it before the mites spread to your other plants.
Preventing Insect Infestations
An ounce of prevention is worth a pound of cure, and that goes double for house plants. It's much easier to prevent insect infestations than to cure them.
- Check house plants every time you water them for signs of trouble. Look for insects - green aphids, white flies, spider mite webs, thrips, everything. Look for unusual webs, bugs, white spots or spots on leaves and stems. If you notice something unusual or unusual changes in your plant, look more closely.
- Know your house plants and provide them with the environment they prefer in nature. Plants can stay healthy if given the appropriate light, moisture and nourishment that nature would provide to them. Look at the plant labels that come with the plant or look up the plant online to find out what conditions it needs, then do your best to provide it.
- Don't kill your plant with kindness! Over watering, over fertilizing and more cause more problems and make plant susceptible to disease. Too much water, for instance, encourages fungus growth near the roots, which in turn provides a ripe breeding ground for the fungus gnat. It only takes one in the house to infest a plant.
- When bringing new plants home, quarantine them for a day or two in a separate room. Commercial greenhouses tend to take good care of their plants and prevent infestations simply because it makes good sense economically to only let health stock in their doors and to treat disease and insect infestations quickly; however, plants received as gifts from friends or purchased at plant sales may have trouble lurking under the leaves. Keep them away from your other plants until you're sure they're healthy.
- When bringing house plants in from their time outdoors in the summer, rinse them thoroughly with water or use an insecticidal soap (according to label directions) as a preventative. Many insects enter the home on the leaves of house plants that have been brought outside for the summer. Visually inspect your plants, and make sure you aren't accidentally bringing critters into the home.
Take a few steps to learn more about your plants, how to care for them, and what to do if you discover an insect infestation in your houseplants. Your house plants will thank you for it.
© 2012 Jeanne Grunert
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