Indoor plant pests: things to know

There are a variety of pests that can cause harm to your houseplants. Some can be a nuisance, while others can seriously cause the health of your plants to suffer. To keep your plants healthy, safe, and beautiful indoors, it’s important to know common pests to keep an eye out for – and how to eradicate the most harmful ones. Let’s find out what types usually attack houseplants, how to do plant pests identification, and how to successfully control and manage those pests.  

Types of Houseplant Pests

Aphids

• What Does an Aphid Infestation Look Like?

Aphids are tiny, round, winged green bugs that consume plant sap. To check for this common pest, examine the undersides of your plants’ leaves and along the stems. These bugs will almost always appear in a cluster. 

Large infestations can seriously weaken plants, resulting in damaged flowers or fruit. It’s better to start treatment quickly if you notice them on your plants as they multiply rather quickly. When infested, plants will display yellowing leaves. As the infestation worsens, the plant’s leaves may stunt, warp, and begin to curl. The leaves and stems may also be coated in a clear, sticky substance called honeydew. This is left behind in aphid droppings.

• What Causes Aphid Infestation?

Usually, a plant will be undergoing some sort of stress. This could be transplantation, crowding, poor soil conditions, or drought. The majority of aphids appear in the spring, just before the ladybugs have come out. Lady bugs are natural aphid predators. 

• How Do You Treat an Aphid Infestation?

Fortunately, these are one of the easiest plant pests to get rid of. An effective treatment plan is to give infested plants a good spray-down with soap and water and collect the aphids in a bucket. For more delicate houseplants, you can also try an organic pesticide like Neem oil or release natural aphid predators, like ladybugs, onto the plants. They can turn the pesky bugs into a quick snack!

• How Can You Prevent Aphid Infestation?

There are a couple of ways you can discourage aphids and help your houseplants remain resilient. First off, make sure that your plants have enough airflow. Houseplants should be spaced adequately apart indoors. Plants in your garden must also be spaced appropriately. Along with this, remove any weeds or debris from the soil around the plants. 

Secondly, keep your plants strong and healthy with the ideal amount of water and quality, compost-rich soil. 

Thrips

• What Does Thrip Infestation Look Like?

Thrips are notorious sap-suckers that can lay their eggs in the tissues of stems, leaves, or flower buds. Damaged houseplants will display leaves with faded streaks and spots. These areas are where sap has been taken from the plant. The leaves will also begin to curl. As the infestation becomes more severe, houseplants may experience growth stunting, and their leaves may fall off. On fruit, thrips leave behind what looks like gray scabs.

Thrips themselves are extremely tiny and resemble transparent lobsters. They can be found on the undersides of your plant’s leaves, in a thick cluster. 

• What Causes Thrips?

Thrips are more likely to damage houseplants that are weakened in some way. For example, if they have been transplanted recently or undergone a drought. Weeds can also serve as a host. The biggest cause is introducing already-infected houseplants from the nursery, however. Always check before buying a new plant. 

• How Do You Treat a Thrip Infestation Indoors?

You can get rid of them with an oil-based insecticide treatment, such as Pyrethrin spray. Spraying this on the plant’s leaves will both poison and smother the pests. Additionally, you can release lacewings and ladybugs, which are natural thrip predators. 

• How Can You Prevent Thrips?

To prevent infestation, clear any debris from your plant pots or garden promptly. You will also want to be vigilant with weeding. Another way to minimize the risk of damage is by planting repelling plants, such as oregano, garlic, basil or catnip in the soil around those plants that are vulnerable to thrips. 

Spider mite

• What does Spider Mite look like?

Spider mites (Tetranychus urticae) are one of the most common types of plant pests. These tiny creatures are tick-like and extremely small. Individual spider mites are hard to see on a plant leaf with the naked eye. 

They have eight legs which is the reason they are considered to be related to spiders (arachnids). They appear in multiple colors including brown, green, yellow, and most commonly, red. These creatures tend to live on the underside of the leaf, making them even more difficult to spot. 

You will probably see the damage before you notice the infestation on the plant. This will appear as spots of brown or yellow on the leaf of your plant. You might observe the “webs” that they create on the leaves. 

The easiest way to identify this pest is to grip the stem, and gently shake the leaf over a piece of paper. The small mites will fall off and should be easy to identify. A magnifying glass will make the process easier. 

• What causes Spider Mite?

Given their small size and weight, spider mites travel with ease. They can easily travel from a neighboring garden or an infected plant that you might bring back to the garden or home. They can travel through the air or attach to shoes and clothing as people move past an infected houseplant. Pets can also bring them into your area. 

While they prefer a hot and dry environment, spider mites will still be present in high humidity. They also like a dusty environment. They love a carbohydrate-rich plant, particularly those that are high in phosphorus and nitrogen, all essential elements for a plant. 

• How to treat Spider Mite

Organic treatments are preferable, because they do not kill the natural predators of spider mites. These pests also have a tendency to develop a resistance to pesticides. Once identified, it is best to prune the infected part of the houseplant or leaf. Dispose of these where they cannot infect other plants. A powerful jet of water also helps to remove the problem. 

If you have a serious infestation, there are effective organic and chemical pesticides that will help like Neem Oil and insecticidal soap. 

• How to prevent Spider Mite

First, ensure that your houseplants are healthy and happy. This will make them more resilient to infestation and damage. Give them enough water and maintain the correct humidity levels where possible. 

Control which plants enter your property, and ensure they do not have spider mites. You also want to ensure you use quality, sterile soil at all times. The other preventative measure is to keep the soil weed-free and remove the debris surrounding the plants as this is an ideal breeding ground for pests and disease.

Centipedes/Millipedes

• What do Centipedes/Millipedes look like?

You’re probably familiar with these pests. These creatures have a distinct, long-body, many-legged look. They tend to be tan, brown, or reddish in color. Despite being considered pests, they’re not actually harmful. In fact, centipedes and millipedes eat other potentially harmful bugs that may live in the soil. For this reason, some people allow them to stay. It really depends on what you would prefer.

• What causes Centipede/Millipede Infestation?

Centipedes are drawn to moisture and plant debris. This can occur when you overwater, or do not keep the soil around your houseplant clear. Centipedes and millipedes also show up to feed on other pests that may appear. 

• How to treat Centipede/Millipede Infestation

To get rid of centipedes and millipedes, decrease the amount that you water. Create a drier environment, and their numbers should taper off. Along with this, remove any debris from the soil around your houseplants, and keep the soil clear. Finally, get rid of any spiders or other bugs in the area. This may call for some pest control.

• How to prevent Centipede/Millipede Infestation

To prevent centipedes and millipedes from showing up in the first place, do your best not to overwater. You can also water the soil directly, so that the stems and leaves don’t get wet (as this will increase the overall moisture). Along with this, keep pests under control, and clear any debris. This usually does the trick!

Mealybugs

• What Do Mealybugs Look Like?

At first, you may think that the fluffy patches on your houseplant are mold or mildew. Actually, the fuzzy, light-colored little areas are common houseplant pests, called Mealybugs. These plant insects can be white, cream-colored, or even brown, and at earlier stages these insects are covered in wax. Their bodies are oval and segmented, and they are tiny (only 1/20 to ⅕ of an inch in size). What you typically see are the females, their young, and the unhatched eggs. The males are quite different, and they have wings like gnats. They are rarely present, however!

The signs of Mealybug infestation and damage are leaves that begin to droop and yellow. As a result of the ‘honeydew’ (droppings) they leave behind, sooty mold may also appear on those leaves. These pests are not deadly, but they can still cause the health and beauty of your plants to suffer. It’s important to keep them in check. 

• What Causes Mealybug Infestation?

Mealybugs are big fans of nitrogen, which, as you may know, is one of the main ingredients in fertilizer. If you over fertilize your houseplants, Mealybugs may become more of a risk.

They like humid environments and may show up if you overwater. These plant insects are also fans of close quarters. To control the environment and allow for optimum airflow, give each of your plants a little bit of space (ideally at least half a foot).

• How Do You Get Rid of Mealybugs?

There are a few things that you can try in order to get rid of these creatures. First, for tough houseplants, you can give them a thorough spray with water. For more sensitive plants, and as a secondary measure, you can apply neem oil. It’s also possible to remove Mealybugs individually with a cotton swab and 75% Isopropyl rubbing alcohol. Finally, consider reducing the amount that you fertilize and/or water! 

• How Can You Prevent Mealybugs?

To help prevent Mealybugs on your houseplants, try to apply a balanced amount of fertilizer. Also, ensure your plants have room for optimum airflow, and take care not to overwater. However, even healthy plants risk being attacked by mealybugs if you bring home an infested plant. To prevent it, carefully inspect plants in a nursery or garden center before purchasing to make sure there are no signs of pests.

• What Plants are Vulnerable to Mealybugs

Almost any houseplant can become infested with them, but tropical plants are at greater risk. Among the plants known to be very susceptible are orchids, succulents, cacti, African violets, begonias, coleus, and amaryllis. 

Scale Insects

• What Do Scale Insects Look Like?

There are a couple of kinds of scale: soft scale and hard, armored scale. These look quite similar, appearing as flakes or shells on a plant’s stem or bark. They vary from white to brown in color.

Scale insects will also leave unpleasant and sticky droppings known as ‘honeydew’ behind. Sooty mold loves honeydew and will swiftly follow it! Scale insects are renowed sap-suckers, and their presence on your houseplants can stunt their growth, cause them to yellow, and generally cause their health to suffer. To prevent them from getting worse or spreading, you’ll want to make sure that they're promptly gotten rid of. 

• What Causes Scale Insect Infestation?

Scale insects are known to enjoy warm, dry environments. If you find these insects in your home, they were probably brought inside by an infested houseplant. You’ll want to do damage control by identifying how far they’ve spread and separate the affected plants until you have the scaly bugs in check. 

• How Do You Get Rid of Scale Insects?

There’s no sure-fire treatment to get rid of scale insects, although a lot of success can be had by directly applying a cotton swab soaked in 75% isopropyl rubbing alcohol. Some luck may also be had with organic pesticides, dish soap, and Neem oil. It’s most effective to take these measures when the scale insects have just hatched. This is when they’re known as crawlers, and they will be vulnerable while moving about and looking for somewhere to attach. 

• How Can You Prevent Scale Insects?

To prevent scale insects, always give potential new houseplants a double check. They may have scale already and will spread it to your plant collection if taken home. Along with this, space your plants to avoid the spread of pests or disease and to allow for the circulation of fresh air. 

Sciarid Flies/Fungus Gnats

• What Do Fungus Gnats Look Like?

Sciarid flies, more commonly known as fungus gnats, look a great deal like fruit flies. These tiny insects have gray, somewhat transparent bodies, and are winged similarly. They are only 3-4mm long, which is quite small. 

Sciarid flies do not harm plants, as they only feed on organic matter, such as fungi, fallen leaves, etc. They can be a real annoyance as they fly about, however! 

• What Causes Fungus Gnat Infestation?

Fungus gnats love moisture and fungus-based mold. This most often occurs when plants are given too much water. Sciarid flies will show up to eat any moisture-caused, fungal mold that may appear. Poor soil drainage is also a potential culprit. To determine the cause of your fungus gnat infestation, you’ll need to take a closer look.

• How Do You Get Rid of Fungus Gnats?

The best way to get rid of these pests is to make your houseplant environment uninhabitable. This can be done by removing any plant debris and the top layer of soil. Also, water the plant less frequently, so that there is less moisture. Applying soap water and/or Neem oil can also help you keep the winged pests in check!

• How Can You Prevent Fungus Gnats?

The best way to control and prevent Sciarid flies is to keep an eye on how much you water your houseplants. As a general rule, let soil dry out before you water it. Along with this, keep any plant debris and potential sources of fungal mold clear. 

Springtails

• What Do Springtails Look Like?

These are oval-shaped bugs, with soft, fleshy bodies and antennae. They are typically dark-colored, and can be tan, brown, gray, or black.

As far as pests go, Springtails are simply a nuisance to houseplants rather than a danger. They will chew on the roots, but they are so small (only 1/16-1/8 in size and nearly invisible to the eye) that the damage is minimal. At worst, they may cause the growth of your houseplant to slow. For this reason, you may still wish to keep them in check.

• What Causes Springtail Infestation?

Springtails are drawn to light and moisture. They are wingless, crawling insects, so they typically enter the home through the foundation or a basement window. These insects may also enter the home on plants that are already infested. With new plants, this is something you’ll want to keep an eye out for! 

• How Do You Get Rid of Springtails?

To get rid of these pests, you will want to remove any sources of moisture, such as leaks in a window or sink. This includes moldy carpet where moisture might get in, which may also call for a vacuum cleaner. For springtails directly on your houseplants, you can apply a combination of dish soap and water or Neem oil.

• How Can You Prevent Springtails?

Springtails flourish in wet and humid environments, and eliminating these factors will help quickly get rid of these bugs. To prevent them, keep your home dry, water your houseplants sparingly, inspect the soil frequently, and keep any debris in your houseplant pots and yard clear!