Spider Mites on Houseplants: Treatment and Prevention

Spider mites are tiny, sap-sucking pests that are found on a variety of houseplants. They are members of the arachnid class, which also includes spiders, ticks, and scorpions. Spider mites are typically less than 1/50 inch long and are often difficult to see with the naked eye. They have eight legs and an oval-shaped body that is typically red, green, or yellow in color.

Spider mites feed on the underside of leaves, piercing the plant tissue with their sharp mouthparts and sucking out the sap. This can damage the plant’s cells and cause a variety of problems

Signs of Spider Mites on Indoor Plants

Spider mites feed by piercing the leaves of plants and sucking out their sap. This can cause a variety of problems, including:

• Yellowing leaves: The first sign of a spider mite infestation is often yellowing leaves. This is because the mites are sucking the sap out of the leaves, which causes them to lose their chlorophyll.
• Brown spots and stippling: Since spider mites feed on the chlorophyll in leaves, this can cause them to develop brown spots or stippling. This is a result of the mites’ saliva, which is toxic to plants.
• Leaf drop: In severe infestations, spider mites can cause leaves to drop from the plant.
• Stunted growth: Spider mites can also stunt the growth of plants. This is because the mites are depriving the plant of the nutrients it needs to grow.
• Fine Webbing: Spider mites will produce fine webbing,. This webbing is a lot finer than regular spider webs.
• Tiny specks on the undersides of leaves: If you look closely at the undersides of leaves or in the webbing, you may be able to see tiny specks that are moving around. These are spider mites.

In severe infestations, spider mites can kill plants.

Spider Mite Target Plants

While spider mites can infest most houseplants, there are some that are known to be spider mite magnets. Some common houseplants that are more susceptible to spider mites include:

• Alocasia: Alocasia plants have broad, thin leaves that spider mites love to feed on.
• Calathea and Maranta: These plants are also known as prayer plants and have delicate leaves that are easy for spider mites to damage.
• Ficus: Ficus plants, such as rubber trees and fiddle-leaf figs, are also common targets for spider mites.
• Palms: Palms have long, slender leaves that can harbor spider mites.
• Ivys: Ivys are popular houseplants that are unfortunately susceptible to spider mites.
• Philodendrons: Philodendrons have large, showy leaves that are attractive to spider mites.

Where Spider Mites Come From

Spider mites are most active in hot, dry conditions, so they are more likely to be a problem in greenhouses and indoor gardens. However, they can also thrive outdoors, especially during the summer months.

There are a number of ways that spider mites can infest a home or garden. Here are a few of the most common:

• On new plants: Spider mites can be brought into the home on new plants. This is why it is important to inspect new plants carefully before bringing them home.
• Through open windows or doors: Spider mites can also be blown into the home through open windows or doors.
• On clothing or pets: Spider mites can also be hitchhike into the home on clothing, pets, or even other insects.

Once spider mites are established in a home or garden, they can reproduce quickly. Females can lay up to 200 eggs per day, and the eggs hatch in just a few days. This can lead to a rapid infestation.

How to Prevent Spider Mites

There are a number of things you can do to prevent spider mites from infesting your home or garden. Here are a few of the most effective methods:

• Inspect new plants carefully: Before bringing a new plant into your home, inspect it carefully for spider mites. Look for tiny, white specks on the undersides of the leaves. If you see any spider mites, you should either return the plant to the store or treat it before bringing it home.
• Quarantine new plants: Once you bring a new plant home, quarantine it for a few weeks before placing it with your other plants. This will give you time to identify any pests before they have a chance to spread to your other plants.
• Wash your plants regularly: Washing your plants with a mild soap and water solution will help to remove spider mites and their eggs.
• Increase humidity: Spider mites prefer dry conditions. Increasing the humidity around your plants will make them less hospitable to spider mites. You can do this by misting your plants regularly or by grouping your plants together.
• Use neem oil as a preventative: Spray a plant periodicially with neem oil to help prevent introducing spider mites, or when bringing new plants into the home.

Treating Spider Mites on Houseplants

There are a number of ways to control spider mites, including:

Physical Removal

The easiest, most natural, and cost effective way to treat a minor spider mite infestation is to physically remove them. You can physically remove spider mites from your plants by spraying them with a strong jet of water or by wiping them off with a damp cloth.

You can also mix a few drops of dish soap with warm water and spray the plant thoroughly.

Isopropyl Alcohol

Isopropyl alcohol, also known as rubbing alcohol, can be used to treat spider mites on houseplants. It is a desiccant, which means that it dries out the spider mites and their eggs, killing them. Alcohol is also a solvent, which means that it can dissolve the waxy coating on the spider mites’ bodies, making them more susceptible to dehydration.

To use alcohol to treat spider mites, simply soak a cotton ball or swab in rubbing alcohol and wipe it down the leaves of the affected plant. Be sure to get both the top and bottom sides of the leaves. You can also spray the plant with a solution of 70% rubbing alcohol and water.

Insecticidal Soap

Insecticidal soap is a natural pesticide that can be effective against spider mites. It is available at most garden centers. To use insecticidal soap, simply mix it with water according to the instructions on the label and spray the plant thoroughly.

Horticultural Oil

Horticultural oil is a type of pesticide that smothers spider mites and their eggs. It is available at most garden centers. To use horticultural oil, simply mix it with water according to the instructions on the label and spray the plant thoroughly.

Neem Oil

Neem oil is a natural pesticide that is derived from the neem tree. It is effective against a variety of pests, including spider mites. To use neem oil, simply mix it with water according to the instructions on the label and spray the plant thoroughly.

Predatory Mites

There are a number of predatory mites that can eat spider mites. These mites are available from some garden centers and online retailers.

Beneficial Insects

You can also try ladybugs or lacewings. These are voracious eaters of spider mites and their eggs. They are a popular choice for biological pest control because they are easy to raise and release, and they are harmless to plants and humans. These are particularly effective in greenhouses or closed environments.

Whatever method you’re using to treat spider mites on houseplants, make sure you spray the entire plant thoroughly. Multiple applications may be necessary.

Additional Tips for Treating Spider Mites

Here are some additional things to keep in mind when treating spider mites:

• Inspect new plants carefully before bringing them home. Spider mites can be brought into the home on new plants, so it is important to inspect them carefully for pests before adding them to your collection.
• Quarantine new plants for a few weeks before placing them with your other plants. This will give you time to identify any pests before they have a chance to spread.
• Keep your plants healthy and well-maintained. Healthy plants are more resistant to pests, so make sure to water them regularly, provide them with the proper amount of light, and fertilize them as needed.
• Monitor your plants regularly for signs of pests. Check your plants regularly for signs of spider mites, such as yellowing leaves, leaf drop, and webbing.
• Use a potting mix that is well-draining. Spider mites prefer damp soil, so using a well-draining potting mix will make it less hospitable to them.
• Avoid overwatering your plants. Overwatering can create the perfect environment for spider mites to thrive.

By following these tips for treating and preventing spider mites on houseplants, you can help to keep your houseplants healthy and free of these pests.