Mealybugs are perhaps one of the most common indoor and outdoor pests out there.
These pests are a type of scale and feed off of your plant’s sap. It can be a little difficult to spot mealybugs before they start a colony, as they often hide on the undersides of leaves.
The nymphs are the most destructive and can kill a plant if the infestation is not stopped. Meanwhile, adults will only survive long enough to breed.
But sucking your plant dry isn’t the only threat mealybugs pose.
Their frass is partially-digested sap, known as honeydew. Honeydew attracts ants, which will protect the mealybugs in exchange for this substance, which they use as a food source.
The honeydew itself attracts fungal spores, especially sooty mold, which can further torment your plant.
List of 9 Natural Mealy Bug Killers
As nasty as mealybugs are, you can combat them without resorting to harsh chemicals.
Here are 9 natural methods that can help you fend off these tiny terrors.
Apple Cider Vinegar
Vinegar can harm plants unless diluted, and apple cider vinegar is mild and effective.
To use, mix one-part vinegar to four parts water and pour into a spray bottle.
Give your plants a good spray down at a time of day when the plant isn’t going to be in direct sunlight.
Apply the solution every few days until the mealybugs are gone.
Diatomaceous Earth
This dust, made from the crushed fossils of diatoms, is harmless to humans and pets but devastating to bugs.
Dust the plant’s leaves with the DE, and it will lacerate any mealybugs that pass over it.
Once the waxy coating and exoskeleton are compromised, the mealybug will dehydrate and die.
The downsides to using diatomaceous earth as a dusting agent:
- it easily dislodges from the plant in a breeze,
- it can also harm beneficial insects, and
- it must be reapplied every time the plant gets wet, as water renders it ineffective.
Essential Oils
Some essential oils can harm your plant, but a few are quite effective when diluted or added to other remedies.
Peppermint oil is the most effective, but citrus oils extracted from the peel are also quite good and may be less abrasive on the nose.
Leaf Shines
A leaf shine is any mixture designed to spray onto a leaf and wipe off to leave the plant dust-free and glossy.
You can buy premade leaf shines or mix your own, such as homemade neem leaf shine.
Most of these products use some form of horticultural oil. Use them when the plant is out of direct sunlight.
The oils will also kill mealybugs and other pests on contact. Reapply a few times per week.
Natural Predators
Outdoor plants have another defender: natural predators.
You will need to prevent ants from having access to infested plants or attacking predators.
Some species known to feed on mealybugs are:
- Lacewings
- Ladybugs
- Mealybug destroyers
- Parasitic wasps
Encourage the native population to help out by planting marigolds, rosemary, and other plants they like.
Or, you can order them online and have them delivered straight to your home.
Neem Oil
The king of horticultural oils, there’s no denying neem’s effectiveness.
There are many types of neem oil and just as many ways to apply it. The most effective are a soil soak using raw neem and a foliar spray with 1% percent clarified neem.
Neem oil is also a popular ingredient in leaf shines.
Related: Killing Mealybugs with Neem Oil
Pruning
Your plant is probably due for a trim, which gives you the perfect excuse.
Isolate your plant and use peroxide or other sterilizing agents to ensure your shears remain disinfected after each cut.
Starting at the top, shield the leaves underneath and begin trimming infested leaves or branches.
Dispose of each piece immediately in a plastic bag or another sealable container.
This method will work best on smaller colonies, but you can also use it to trim off the worst portions and use other methods as a follow-up.
Soap
Some plants are sensitive to soap, but a touch of gentle soap in water can not only kill mealybugs but help keep your plants clean and healthy.
Mix one tablespoon of soap into a quart of water, spray down the plant and wipe dry.
We recommend Dawn dish soap, pure Castile soap, or insecticidal soap,
Note that this method is similar to leaf shines but more concentrated. Be sure your plant is tolerant of soap before using.
Water
Sometimes a hose is enough to deal with these little pests. The water pressure will dislodge mealybugs and send them flying.
This method won’t actually kill them, and there’s always the risk of sending them into another plant or overwatering the one you’re treating.
Still, it’s an excellent method to use in the house if you have a detachable showerhead and have plants that prefer a soak-and-dry method of watering.