How To: Get Rid of Mealybugs
These hard-to-spot pests not only harm plants, they invite other pesky insects to the party. Follow this guide to banish mealybugs from your home and garden.
Your beautiful garden and potted indoor greenery are equally vulnerable to mealybugs, tiny yet destructive pests that literally sap the life out of plants. Mealybugs can stunt growth, wilt and yellow foliage, and mar the appearance of stems, nodes, and leaves with waxy white residue. What’s more, that sticky stuff they excrete—called mealybug honeydew—attracts other insects that feed on it. The trickiest thing about these invaders is that they can be hard to recognize, until you see evidence of their destructive ways. So use this guide to spot mealybugs and send them packing, for good!
The 411 on Mealybugs
In small numbers, mealybugs can’t do too much damage. Unfortunately, after sneaking in on the undersides of leaves, petals, and protected areas at the base of plants, they can multiply unnoticed for some time. So it’s best to keep an eye out for signs and battle mealies right away.
What Are Mealybugs?
Members of the Pseudococcidae family, with some 275 species in the United States, mealybugs wreak havoc by piercing stems and leaves and sucking out the sap. They are drawn to all kinds of vegetation, particularly in warmer climates, targeting fruit trees, crops, and ornamental plants such as orchids, gardenia, English ivy, fuchsia, coleus. They can attack outdoor and indoor plants, and can be especially invasive in greenhouses.
What Do Mealybugs Look Like?
Sneaky, slow-moving mealybugs definitely don’t resemble typical insects. Females have soft, white, oval-shaped waxy bodies, 1/10- to 1/4-inch in length, which makes an infestation appear more like tiny cotton balls than bugs. Males have wings and are much smaller. Many mealybug species have numerous projections along the sides that look like legs.
Once mealies find a feeding spot on a plant, they may gather together in an immobile cluster. Also be on the lookout for the bugs’ sticky excretions, which is often accompanied by black, sooty mold.
What Is the Mealybugs Life Cycle?
Female mealybugs have four life stages while males have five. Life cycle varies depending on species, but typically the female lays up to 600 eggs in a cotton-like pouch. Hatchlings, called “crawlers,” emerge in 1 to 2 weeks and creep slowly to one spot where they feed until maturity, which takes between 1 and 2 months. While males die soon after fertilizing females, and females die within days of laying eggs, several generations of mealybugs can reproduce in the course of a year.
Where Do Mealybugs Come From?
A mealybug problem often surprises gardeners because it seems to occur mysteriously. Often, the pests enter a situation via other plants from the nursery. They are also attracted to warmth and moisture, so they may gravitate toward over-watered plants.
How to Get Rid of Mealybugs
Fast action is required as soon as you find your plants are hosting these pests. Try the following methods to make short work of banishing mealybugs.
Method 1: Remove Mealies Manually
If you catch a mealybug problem early, and there isn’t a prohibitive number of pests present, hand-pick the pests from plants. Mealies don’t bite or carry diseases, so it’s fine to snatch them off with your fingers. For potted plants, a drop of isopropyl alcohol on a cotton swab will help penetrate the wax on the bugs’ body to remove them more easily. (Spot test on a small part of the plant ahead of time to make sure it won’t cause leaf burn.) For sturdy garden plants and fruit trees, spray with forcible streams of water from a garden hose to knock off large numbers of mealies.
Method 2: Introduce Natural Enemies
Certain predatory insects such as parasitic wasps, lacewings, predaceous midges, as well as spiders, can help keep mealybug populations under control. The mealies’ arch enemy, however, is the black ladybug Cryptolaemus montrouzieri. Commonly known as the mealybug destroyer, the species is available at garden centers and online. Add two to five destroyers to a plant and let them feast!
Method 3: Control the Ant Population
While black ladybugs are the mealybugs’ enemies, ants are their chief allies. Ants protect mealybugs from predators so that they can continue dining on syrupy honeydew that mealybugs excrete. Combat ants naturally by encouraging their predators, which include ladybugs, hoverfly larvae, lacewing larvae, and entomopathogenic fungi. Also employ these control techniques if you spot unusual numbers of ants on plants. If you don’t get rid of the ants first, it will be more challenging to defeat the mealybugs.
Method 4: Clean or Remove the Infested Plant
It may be possible to salvage a heavily infested plant, depending on species, by carefully uprooting and cleaning it. Succulents, for instance, can be lifted from their soil and washed thoroughly under running water; allow to dry thoroughly before replanting.
Sometimes, alas, the best course of action is to sacrifice the source plant to minimize further spread. Once you’ve removed it, inspect pots, tools, and other materials that may have come into contact with the plant for mealies and their egg sacs. Clean or discard any that show signs of infestation.
Method 5: Try Insecticide
Mealybugs’ waxy coating is like armor that the chemicals in many insecticides cannot penetrate. However, some insecticides may be effective against young mealybugs that haven’t yet developed their full waxy covering. Insecticidal soaps, horticultural oil, or neem oil insecticides may provide some suppression.
Multiple applications will likely be needed for best results. Rather than rely on one product, rotate insecticides each time to delay resistance. Make sure to apply thoroughly to the undersides of the plant where mealybugs often hide.
How to Prevent Mealybugs From Returning
Now that you’ve conquered the creatures, vigilance will help ensure that mealybugs never get into your garden or houseplants again. Always inspect new plant purchases for sticky honeydew and black mold on leaves before bringing them home. Keep ants at bay and invite the natural enemies of ants and mealybugs to your landscape.
FAQ About How to Get Rid of Mealybugs
Will dish soap kill mealybugs?
Dish soap can indeed be an effective weapon against mealybugs when used on certain plants, particularly tomato plants. Mix 2 teaspoons of dish detergent in 2 cups of filtered water in a spray bottle and test it on a few leaves to ensure it won’t damage the plant. If all seems clear, spray both sides of leaves until the entire plant is wet with the solution, which will stick to mealybugs and ultimately suffocate them. Hose off gently after about four hours to remove bugs.
How do I get rid of mealybugs in soil?
Root mealybugs are a species that live in soil and feed on plant roots. Soil soaks containing neem may be effective against root mealybugs and other underground pests without harming beneficial earthworms.
What is the life cycle of mealybugs?
Eggs hatch in 1 to 2 weeks and take between 1 and 2 months to reach maturity. Adults die within days of fertilizing and laying eggs.