If you’ve been growing houseplants in your home, you may have had an encounter with some of the five most common houseplant pests. Many people like to grow plants in their homes. They bring a little of the outside in and can provide fresh herbs for your favorite recipe. However, if you find your favorite plant is feeling a little wilted, you may be dealing with more than just a lack of routine watering.
Houseplants can bring humans many benefits. From food to aesthetics, some even find a sense of calm in caring for a living thing. But with them, plants can also invite unwanted visitors into your home in the form of insects. Some insect species also attract other unwanted pests into your home, like ants. Unless you are content with letting geckos run loose or have no problems with lacewings or ladybugs inside your home, you should be aware of these common houseplant insects and what to do about them.
There are many species of aphids, but the most common you will find on your houseplants is the Pear Aphid. These little green suckers will suck the life right out of your plants. They mainly attack stems and the underside of leaves. You can quickly tell you have them if your plants develop a shiny look to their leaves and begin to curl at the edges. If you don’t spot them right away, look on the undersides of the leaves where they hide.
The problem with aphids on your houseplants is that they not only destroy the plants themselves by sucking the plant juices out of them, but they bring problems two-fold. First, if left untreated, they can cause black sooty mold, which is not only unsightly to look at but can also destroy the photosynthesis process of the plant. Secondly, because these little pests produce excrement known as “honeydew,” many bugs, including ants, are attracted to them. So, another way to tell if you have aphids, is if you see ants marching along your plants.
You can easily control aphids by spraying them with the kitchen hose, attempting to knock off as many as possible from the leaves. Next, make a solution of soapy water to coat the leaves. Avoid using strong chemical detergents, like those with an active degreaser, but rather mild soaps and a high ratio of water to soap. You don’t want to destroy your plants; you just want to keep the aphids from reappearing. Ladybugs and lacewings are also natural enemies of aphids, so you can also remove your plants from the house and let these natural predators do their work. Lacewings are known to entomologists as aphid wolves because of their voracious appetite for the little plant suckers.
If you find your leaves are yellowing, or suddenly dropping, then you might have a whitefly problem. Whiteflies look like moths but are neither flies nor moths. They are part of the true bug family and more closely related to aphids. Whiteflies do fly. However, they are content to stay on the underside of the leaves sucking the juices from the plant. If you happen to disturb your houseplant infested with whiteflies, you’ll suddenly see a white cloud of these flies appear. The most common indoor whitefly is the ficus whitefly.
Whiteflies produce the honeydew excrement, so like aphids, can cause black sooty mold to form and will also attract ants. Some species can also transmit plant viruses. Whiteflies are tiny, most only measuring just 1/16” in length. The Ficus whitefly has shiny white wings and yellowish body with dark mouthparts used to suck the juices from the stems and leaves. Whiteflies attack a wide variety of plants, but in the home, you will most likely find them on Ficus trees and various palms. To rid yourself of a whitefly problem, use yellow sticky traps to catch them, or you can simply vacuum them up. However, make sure not to damage your plants in the process and use a vacuum with a bag where the flies cannot escape upon cleaning. Insecticidal soap can also be used often to spray down leaves and prevent many plant-sucking insects from taking up residence on your favorite houseplants. Organic Gardening magazine has created this recipe for homemade “kitchen insect spray,” which works well on whiteflies.
1 garlic bulb
1 small onion
1 tsp cayenne pepper
Combine all ingredients in a food processor or blender until paste forms. Mix with 1 quart of water and steep (like tea) for 1 hour. Strain through a cheesecloth and add 1 Tbsp mild liquid dish soap (make sure it does not contain a degreaser). Mix well, store in the refrigerator for up to one week.
Mealybugs look like little puffs of cotton on your houseplant’s stems. They are closely related to scales and are sucking insects. Mealybug damage results in yellowing of leaves, early leaf drop, and stunted growth of plants. Mealybugs also produce honeydew that causes black sooty mold and attracts ants. There are roughly 275 species of mealybug, but the long-tailed mealybug and the citrus mealybug are the two commonly found on houseplants. Mealybugs are generally transferred into the home via another plant. Make sure to scrutinize all houseplants before bringing them inside.
If you find you do have mealybugs, a cotton swab soaked in rubbing alcohol is the best defense against these pests. A good spray of water will also knock off most insects. Make sure to inspect all plants in the home as an infestation usually becomes more problematic to deal with the more the population spreads. Infested plants that cannot be controlled are best discarded and replaced with insect-free plants before they begin to attack other plants in your home.
There are over eight thousand different species of scales, but the common brown scale is the one most indoor gardeners deal with. These pests can be extremely tedious to control. Many plant growers would rather toss their plants than deal with removing these little buggers. Brown scales look like little turtles that have attached themselves to the stems of your plants. Once they take up residence suctioning onto your plants, they do not move. However, young scales do move around until they find the perfect spot to dig into your houseplants.
Scales, like all the pests on this list, also produce honeydew, which attracts ants and can cause sooty black mold to grow. You can tell you have a scale problem if you find a thick honey-like substance dripping off the stems of your plants. This honeydew will drip onto areas surrounding your infested plant.
Getting rid of them is the problem. Use an insecticidal soap to work up a good lather and then scrape the pests off with your fingernail. (Yuck)! Neem oil will help prevent re-infestations. But this is where plant owners usually just discard the plant and replace it with a new one. Scales can be stubborn, and it may take many sessions of soaping and scraping before the problem is resolved.
Neem oil by Safer has the best reputation for quality:
Spider mites are not insects, but rather arachnids. They have eight legs instead of six and two-segmented body parts like all spiders. You can quickly tell you have spider mites due to the fine webbing they leave all over an infested plant. Spider mites, like aphids, are juice-suckers. They have chewing mouthparts that attack the stems and leaves of your plants, causing them to wilt. Spider mites prefer edible plants like herbs and ornamentals.
If you see the webbing, you can be sure you have them, but you can also take a piece of white paper and place it underneath the plant. Next, gently shake the plant, and you’ll see the little orange spider mites scurrying around on the white background. These insects are only 1/50,” so you won’t see them crawling on the plant, but you will on the white paper background.
Most often, spider mites happen due to a lack of watering. These insects don’t like humidity, so keep your plants hydrated regularly, and these tiny pests shouldn’t be a problem. If you do find you have them, like aphids, take a blast of water from your kitchen sink and knock off as many as possible. A soapy solution of mild detergent can be used to prevent re-infestation. Horticultural oils also exist that will help prevent spider mites from reappearing.
Here is a popular, horticultural oil that you can keep on hand:
Tips to keep your plants pest-free:
- Check all plants for insects before bringing them into your home.
- Quarantine new plants away from others for 7-10 days to prevent any accidental infestations
- Keep your plants at their peak hydration level. Healthy plants are less attractive to pests
- Use mild insecticides and neem oil to prevent insects and fungus from attacking your plants
- Coldwater sprays and soapy spritzes will knock off pests from your plants and help keep them pest-free.