Plants infested by mealybugs? I know you're frustrated, but don't give up! Unless your plants are severely infested, there's a good chance that you can save them. Mealybugs (Pseudococcidae) are nasty little sap-sucking insects that can do serious damage to plants. They're also a common problem for houseplants, greenhouse plants, and outdoor plants in warm climates. Find out what you can do to free your plants from these invaders and how to minimize your chances of having to deal with future mealybug infestations once you get rid of them.
Verify Mealybug Infestation
Are you sure that mealybugs are what you're dealing with? Mealybugs are usually light pink or yellow, but may appear white because they are often covered by white tendrils that give them a cotton-like appearance. They are tiny (usually around 1/8 of an inch long) oval-shaped insects, but don't let their size fool you. They like to cluster together on plants and can do a lot of damage.
- Mealybugs use their piercing mouthparts to suck the sap out of whatever type of plant they are on, damaging or even destroying their leaves.
- They also produce sticky honeydew that sticks to the leaves of plants and attracts sooty mold and leads to fungus-insect gall.
8 Ways to Get Rid of Mealybugs
Are your suspicions confirmed now? If so, don't delay! If possible, isolate any infested plants while you are treating them to help keep mealybugs from spreading to other plants. There are several ways to deal with mealybugs. The sooner you get started, the better.
Pick Them off Affected Plants
Unless a plant is completely infested with mealybugs, you can hand-pick them from your plants to remove them. This may seem yucky, but it's a good natural option that will work. Be sure to wear gloves if you do this. Don't just put them outside, as they'll infest something else. It's best to squish them or drop them into a container of soapy water to drown.
Dab an Alcohol Solution on Mealybugs
If you can't bring yourself to pick mealybugs off your plant, you could opt to use rubbing alcohol (just regular household alcohol like you buy at the drugstore) on them. Just dab the rubbing alcohol directly onto the insects with a cotton swab. Take care to keep the alcohol from coming directly in contact with the plant itself, as it could damage the plant.
Prune Infested Leaves or Branches
If the mealybug infestation seems to be limited to just a few leaves or branches of infested plants, you could prune away the ones that are the most infested and destroy them. If you do this, take the time to visually inspect the entire plant. The idea is to look and see if there are any errant mealybugs elsewhere that need to be picked off or dabbed with alcohol.
Spray Insects and Leaves With Neem Oil
Spraying infested leaves with neem oil or another type of horticultural oil spray can help get rid of mealybugs. If you go this route, you'll need to be sure to thoroughly coat the insects with spray. It's a good idea to go ahead and thoroughly coat the leaves as well when applying horticultural oil, as it can serve as an organic pest repellent to help keep other pests from infesting the plant.
Blast Plants With High-Pressure Water Spray
Another option is to hit the plant with a high-pressure stream of water from a hose several times per day for a few days in a row. This is a better option for outdoor plants than houseplants. You won't want to do this with relatively small houseplants, as the water could damage them. You'll need to take houseplants outside several times to do this. Depending on the plant and the weather conditions, this could be harmful to the plant.
Douse Plants With Insecticidal Soap
You can also get rid of mealybugs by dousing the plant with insecticidal soap. For severe infestations, this is the best place to start. Some sources suggest making your own solution for this purpose by mixing dish soap with water. This can kill mealybugs, but it can also damage your plants and kill beneficial bugs. Since you want to get rid of mealybugs to protect your plants, the better option is to purchase commercially-made insecticidal soap from a garden center.
Treat Soil With Insecticide
For severe issues, you may want to apply insecticide to the soil in which the infested plants are protected. Some university-based extension services recommend systemically applying an insecticide that contains dinotefuran for this purpose. This will not immediately kill mealybugs on your plants, but will help control them long term. Before using this substance, you should be aware that it is toxic to bees and other beneficial insects.
Know When to Say When
I know it's not easy to accept, but not all plants can be saved from mealybug infestations. If the methods above don't work - or if your plant is so covered in mealybugs that it's not even worth trying - you will need to get rid of the plant (along with the bugs that are infesting it). Don't be discouraged if it comes to this. It can be extremely difficult to eliminate mealybugs once they manage to heavily infest a plant.
What About Vinegar?
Some sources suggest using vinegar to kill mealybugs. This may technically work, but I don't recommend it because it can harm plants and change soil acidity. Vinegar is so likely to damage plants that it is actually used as an herbicide. Now, herbicidal vinegar is stronger than the vinegar you have in your house, but that doesn't mean that home-use vinegar couldn't harm your plants, even if you dilute it. It is especially dangerous for young or small plants, as well as ones that are in already weakened conditions. With so many better options to get rid of mealybugs, don't put your plants at risk by using vinegar in this way.
Ideas to Help Keep Mealybugs Away
To prevent future severe infestations, inspect your houseplants, greenhouse plants, and warm weather garden regularly so you can act decisively to get rid of mealybugs at the first sign of infestation. As long as you catch them before they spread, you should be able to get rid of them and save your plants. During the summer, be diligent in watching for mealybugs on outdoor plants as well. If you are shopping for plants to bring home, look closely at the leaves to make sure you aren't bringing along any interlopers - in the form of mealybugs or any other garden pests - for the ride.