How to Get Rid of Mealybug Infestations on Houseplants

Mealybugs are one of the most common houseplant infestations and easiest ones to misidentify as their waxy coating makes them look like cotton balls or sometimes pieces of perlite from the potting mix you’re using. These pests tend to group on stems as well as in crevices and leaf joints where perlite may get stuck.

There’s over 2,000 known types of mealybugs with 275 species in the continental United States. While they can survive outside, they prefer warm and humid climates, which is why they thrive inside and on houseplants. They get warmth from our homes or in a greenhouse, and once established, they eat the sap from the plants. 

Fun fact: The only continent Mealybugs do not live on is Antarctica. The only insect that lives on and is natural to Antarctica is the Antarctic Midge.

Mealybugs damage plants by sucking the sap out of them causing yellowing, leaf drop, stunted growth, and sometimes death. They can also secrete a sticky goo called “honeydew” that is sweet because of the sap and can attract other insects like ants while also causing sooty mold and black fungus to grow. 

These pests can reproduce up to 6 times per year in the right conditions, and some species can lay between 100 and 600 eggs, so the minute you spot them you want to treat your houseplants before they spread. And that’s what we share below. But first, here’s how to identify them.

In order to treat a Mealybug infestation, you have to know they are in fact Mealybugs as they can look similar to some wooly aphids, molds, and whiteflies. To identify a Mealybug and its infestation look for:

• White cottonlike masses on plant stems, leaf joints, and leafs

• Sticky residue on the plant

• Black sooty mold and fungus growth

• Tiny oval shaped and soft insects that are yellowish or tan colored, light grey, and sometimes pinkish with segmented bodies. 

  • You’ll find them, under the layers of cotton like masses.

The cotton-like masses are different from Spider Mites which will have 8 legs and be more like webbing and silk.

Fun fact: Mealybugs and ants have a symbiotic relationship where the ants protect the Mealybugs as they use their honeydew as a food source. This has been documented many times, so if you see ants and the cotton like substances, there’s a good chance it is a Mealybug infestation.

There are three ways to treat plants with Mealybug infestations:

• Wipe them off of the plant and using rubbing alcohol

• Use an insecticide (natural or chemical)

• Introduce predators (for outdoor infestations)

Each of these strategies starts with isolating the infected plant so the Mealybug infestation cannot spread to others.

Here’s how to do each, the frequency, and then some tips to prevent a reinfestation.

This is the best option for treating small and isolated indoor Mealybug infestations. Before trying this method, do a sample test on a leaf of the plant to make sure the rubbing alcohol does not cause leaf burn and kill the plant. If it does, you'll want to use one of the other two options.

You will need:

• Cotton swabs

• Rubbing alcohol (70% isopropyl)

• A sink with a sprayer (optional)

To get rid of the minor infestation:

1. Inspect the entire plant including joints, new leaf growth, the undersides of the leaves, and near the potting mix to identify all infestations.

2. Dip the cotton swab into the rubbing alcohol and dab each individual cotton-like growth and Mealy bug directly.

3. Any leaf or spot that has a larger infection should be pruned off of the plant and the pruned part should be thrown out immediately.

4. Once everything has been treated and is dry, rinse the plant with a sprayer or under the sink to remove excess alcohol and wash the Mealybugs away. 

5. Repeat if necessary.

Insecticides can be used to treat mild to moderate Mealybug infestations on indoor plants.

You will need:

• One bottle of plant safe insecticide

• A spray bottle

• A clean cloth

To get rid of mild to moderate infestations:

1. Wipe any visible infestations off with the clean cloth, while changing clothes out and rinsing them to make sure you don’t accidentally spread Mealybugs.

2. Mix the insecticide following the instructions on the container.

3. Apply the mixture to all affected areas of the plant including the undersides and let it dry.

4. In 10 to 14 days, mix another batch of the insecticide and pour it in a spray bottle to treat the plant again. This may be done a few times to ensure the Mealybug infestation is gone.

For severe infestations and repeat Mealybug infestations on outdoor plants, you may want to introduce predators that will eat or kill the Mealybugs without causing damage to other plants and the local ecosystem. Once the infestation has been consumed the predators will normally leave the area or die off.

Some Mealybug predators include:

• Lady Beetles (Ladybugs)

• Green Lacewings

• Minute Pirate Bugs

• Crab Spiders

There is a catch here, if you use predators to get rid of an outdoor Mealybug infestation, you cannot use insecticides and other treatments as it will kill the predators.

Although you cannot prevent a Mealybug infestation 100% of the time, you can take steps to reduce the frequency and prevent it from spreading Here’s a few tips:

• Keep plants healthy and avoid over and underwatering as weak plants are more susceptible to an infestation. Overwatering and high humidity create the perfect breeding ground for Mealybugs as they thrive in warm, humid, and tropical environments.

• Inspect every new plant and keep it separated for a few weeks to help make sure you don’t bring a new infestation into your collection.

• Treat each new plant you bring into your home with an insecticide before you introduce it to the collection.

• Twice a month give your plants a spray with an insecticide, or every two weeks if that is your watering schedule, making sure to get the undersides of the leaves, flowers, and anywhere else Mealybugs may hide.

Mealybugs are one of the most common houseplant infestations. They’re also one of the easiest to treat. It could be as easy as dabbing them with rubbing alcohol or treating the infections with insecticides.