Mealy Bugs: How To Get Rid Of Mealybugs [CONTROL GUIDE]

Most people want to know one thing: how do you get rid of mealybugs?

They usually ask after spotting small, white, cottony clumps on an indoor plant or on an ornamental plant in the landscape. If the fluff sits where leaves meet stems and the leaves feel sticky, mealybugs are a likely suspect.

Here’s the honest part first. Mealybugs are very difficult to manage with insecticides. The good news? Caught early, a small infestation on a houseplant is very manageable with patient, simple steps. Let’s walk through what works, what to skip, and when to let a plant go.

What Do Mealybugs Look Like?

Mealybugs are soft, oval insects covered in white wax. Most adults are wingless females with segmented bodies; males have wings but are rarely seen. Missouri Botanical Garden says a typical female is 1/16 to 1/8 inch long, and some species reach 1/4 inch.

They are piercing-sucking insects, close relatives of plant scale bugs, in the order Hemiptera, along with scales, whiteflies and aphids. They usually feed in colonies in protected spots: the crown of a plant, branch crotches, stems near the soil, and between a stem and the leaves touching it. A few species feed on roots.

Not every white, waxy speck is a mealybug. They can be confused with cottony cushion scale, woolly aphids, soft scales and whiteflies, so look closely at the insect under the wax.

These are among the most common pest mealybugs:

• Citrus mealybug (Planococcus citri), the most common mealybug on indoor ornamentals
• Longtailed mealybug (Pseudococcus longispinus), which gives birth to live young instead of laying egg masses
• Obscure mealybug (Pseudococcus affinis)
• Grape mealybug (Pseudococcus maritimus)
• Vine mealybug (Planococcus ficus)
• Ground mealybugs (Rhizoecus species), which live in the soil and feed on roots

There is also the pink hibiscus mealybug (Maconellicoccus hirsutus), whose saliva is especially toxic to plants. The UF/IFAS Extension Charlotte County office adds that Florida has many mealybug species, with names like pink hibiscus, pineapple, citrus, papaya and coconut.

What Damage Do Mealybugs Cause?

Mealybugs suck sap, which weakens the plant. High populations can slow growth and cause leaf drop. Heavily infested plants can show irregular or no growth, yellowed leaves and significant leaf drop, and left untreated, plants can die. Mealybugs also inject chemicals that cause distortion, stunting and yellowing.

They also excrete sticky honeydew, which can make leaves and floors sticky. A black fungus called sooty mold grows on the honeydew. Sooty mold doesn’t injure a plant directly, but it blocks sunlight from leaves, reducing photosynthesis.

The upside: healthy plants can tolerate low populations without significant damage. Catch them early and you have plenty of options.

Watch for Ants on the Honeydew

Ants crawling up and down a plant are a clue worth following. Ants feeding on honeydew are a sign of mealybugs, and ants protect mealybugs from their natural enemies. Ants may also carry mealybugs from one plant to another.

How Fast Mealybugs Multiply

Life cycles vary by species and temperature. Adult females of most species lay 100 to 200 or more eggs in cottony egg sacs over 10 to 20 days. The University of Wisconsin-Madison Extension says citrus mealybug females lay up to 600 eggs. Eggs hatch in 1 to 2 weeks, and females reach adulthood in about a month.

Newly hatched mealybugs, called crawlers, have no wax and move around, but they soon settle down to feed and start making their waxy coat. All stages may be present throughout the year indoors, and indoor plants are especially vulnerable because year-round mild temperatures favor mealybugs and indoor plants are usually not exposed to the natural enemies that keep them in check outdoors.

Mealybugs on Houseplants: Which Plants Get Them Most?

Colorado State University Extension lists these houseplants as the ones most commonly affected:

• African violets (ground mealybugs on the roots are a particular problem)
• Aglaonema
• Dieffenbachia
• Some dracaenas
• Most ferns
• Ficus
• Jade plant
• Norfolk Island pine
• Some palms
• Philodendron
• Pothos
• Schefflera
• Streptocarpus
• Yucca, including the spineless yucca

Other houseplant lists add coleus, cactus, hoya, orchids, poinsettia and herbs such as rosemary and sage. For more on these, see our guides to cactus mealybugs and succulent mealybugs.

Beyond houseplants, citrus, grapes, bird of paradise, cactus, coral bells, cypress, fuchsia, hibiscus and mimosa are among the most commonly infested plants. Figs, flax grasses (Phormium), gardenia, jasmine, Miscanthus grasses and oleander are among the woody and perennial plants mealybugs attack. Among fruit trees, citrus has the most problems.

How To Get Rid of Mealybugs

Here’s the blunt truth: their waxy coating repels most contact insecticides, and their habit of hiding in tight spots makes them hard to reach. So the best plan combines several steps, starting with the gentlest.

Start With Prevention

Mealybugs are often brought in on new plants, tools or pots. Examine, quarantine for 2 or 3 weeks, and treat as needed all new plants before placing them near mealybug-free plants. If you can’t remove all the mealybugs from a new plant, discard it or take it back to the source.

Once you’ve found mealybugs, keep checking plants, pots and stakes on a regular basis and dispose of infested items. Go easy on fertilizer, too: high rates of nitrogen combined with regular irrigation may stimulate tender new growth as well as mealybug egg production.

Hand Removal and a Water Spray

For a houseplant, the first step is to hand pick the mealybugs or prune them out. On sturdy plants, a forceful spray of water can reduce exposed populations, repeated every few days as needed; a moderately strong spray of warm water works. Dispose of pruned cuttings right away, because mealybugs can survive on detached plant parts as long as those parts stay moist.

Manual removal is unlikely to eliminate mealybugs, but it can often keep an infestation within tolerable limits without harming beneficial insects.

Rubbing Alcohol: The Right Way

As with soft scale insects, alcohol on a cotton swab is a popular spot treatment. For small infestations on houseplants, the University of California Statewide IPM Program (UC IPM) says a 70% or less solution of isopropyl (rubbing) alcohol in water may be dabbed directly on mealybugs with a cotton swab to kill or remove them. Test the solution on a small part of the plant 1 to 2 days beforehand to make sure it doesn’t cause leaf burn. In some cases a much more diluted solution may be advisable.

Where infestations are extensive, a 10-25% solution of isopropyl alcohol can be applied with a spray bottle, repeated every week until the infestation is gone. A similar option is a mix of 10 percent rubbing alcohol and 90 percent water sprayed directly onto the insects, repeated weekly, after testing on a small part of the plant. Our step-by-step guide covers killing mealybugs with alcohol.

Not every extension service is comfortable with alcohol on leaves. UF/IFAS Gardening Solutions lists vinegar and alcohol as phytotoxic ingredients that cause leaf burn and says they should not be applied to plant tissues. That’s one more reason to test a small area first and stop if you see damage. It may take a day or two for symptoms to show.

Skip the Dish Soap and Kitchen Recipes

You’ll find plenty of homemade sprays online that mix alcohol, dish soap and even neem oil. Skip them. Dish “soaps” are really detergents designed to be powerful cleaners, and even watered down they can cut through the waxy layer that protects leaves, often leaving damaged, dry, crispy leaves.

Mixing different products in home recipes is also dangerous, because common cleaners that are safe on their own can be toxic to people when used together. A university IPM statement on homemade pesticides says homemade mixtures generally haven’t been tested in replicated research trials, and that recommendations of oils and soaps mean products formulated for use as pesticides, not household soaps and oils.

Insecticidal Soap, Horticultural Oil and Neem Oil

Insecticidal soaps, horticultural oil or neem oil insecticides applied directly on mealybugs can provide some suppression, especially against younger nymphs that have less wax. Test them on part of the plant first, just as with alcohol.

Treat when crawlers are present, spray thoroughly because mealybugs hide under leaves and in crotches, and repeat applications as the label directs. Spot treat with insecticidal soap or horticultural oil as per label directions, and not in the heat of the day, since it can burn the leaves.

Buy a product registered as an insecticidal soap rather than using a dish detergent. Properly registered insecticidal soaps are usually only 1-2% soap by volume, and plants under drought stress, in excessive humidity or in heat above 90°F should never be treated with soaps. Mixing rates differ from product to product, so follow the label on the one you buy.

Neem oil comes from the seeds of the neem tree and is sold at garden centers. It is a pesticide, so treat it like one. The National Pesticide Information Center (NPIC) says neem oil can be slightly irritating to the eyes and skin, is slightly toxic to fish, and its azadirachtin component is moderately toxic to fish and other aquatic animals. It also reports adverse reactions, some fatal, in cats treated with neem oil for fleas in other countries.

Don’t count on neem lasting long on the leaves, either. Azadirachtin breaks down quickly on plant leaves, with a half-life of 1 to 2.5 days. See our guides to neem oil on mealybugs, neem oil for plants and applying neem oil, which explains why the label rate on your bottle comes first. Neem is also used to clean plant leaves.

Whatever you use, read the pesticide label and wear the appropriate safety equipment it calls for.

Systemic and Other Insecticides

Plant spikes or granules containing the systemic insecticide imidacloprid may reduce mealybug crawler numbers on houseplants. These neonicotinoid products are less reliable against mealybugs than against other piercing-sucking insects, though, and their use should be avoided when possible, especially on flowering plants, because of potential harm to natural enemies and pollinators.

Sources differ on the sprays. Pyrethroid sprays are described as usually effective for mealybug control, and acephate, bifenthrin and pyrethrins are listed as effective. Others warn that pyrethroids may not be much more effective than soaps and oils and can be devastating to natural enemies.

Always follow the product’s label and make sure the product is effective against mealybugs; not following the pesticide label is a violation of federal law.

Natural Enemies: Mostly an Outdoor Option

Outdoors, natural enemies do a lot of the work: parasitic wasps, lady beetles, green and brown lacewings, spiders, minute pirate bugs and predaceous midge larvae. The mealybug destroyer lady beetle, Cryptolaemus montrouzieri, is the most important of these predators in many areas. Another option, the parasitic wasp Leptomastix dactylopii, is sold for greenhouses, citrus groves and interiorscapes, but it kills only the citrus mealybug.

For a houseplant, buying predators is less practical. Most natural enemies are not appropriate for use in the typical home. There is little point in releasing mealybug destroyers when mealybug numbers are low or not reproducing, because the beetles need mealybug eggs to reproduce. More ideas are in our guide to natural mealybug control.

If your plants grow outdoors, protect those natural enemies: avoid broad-spectrum insecticides and keep ants out of infested plants.

Know When To Let a Plant Go

None of the available insecticides will likely provide complete control, so plan to monitor and treat again as needed. When infestations become severe, consider discarding houseplants rather than repeatedly treating them with insecticides. Root infestations are particularly difficult to control, so replacing the plant is often the most practical fix.

Mealybug Treatment on Orchids

Orchids are among the houseplants that often have mealybug problems. On orchids, look in the leaf joints, under leaves, on buds and in crevices of the pot.

The American Orchid Society (AOS) takes a different view of alcohol than the 70% dab described above. It says spray-on contact insecticides such as insecticidal soap and horticultural oil are the most effective control, along with crushing mealybugs with a cotton swab, and that alcohol is not very effective against mealybugs and can strip away the plant’s waxy cuticle. It recommends disturbing the colony first by wiping away the mealy powder or washing the bugs off, then following up with insecticidal soap, and says 3 to 4 applications at intervals of a few days typically do the trick indoors.

If you use alcohol on an orchid anyway, stick to the 70% or less dab and test a small spot first.

Where Orchid Mealybugs Come From

Prevention is the best treatment. Mealybugs usually arrive on:

• New plants added to your collection
• Plants that spent the warm months outdoors (plants summered outdoors can be attacked)
• Ants carrying them from plant to plant
• Pots, tools and stakes from infested plants

Inspect and quarantine every new orchid before it joins the collection. If mealybugs are on buds or flowers, prune them out: losing a bloom spike beats losing the plant. Also see how to get rid of mealybugs on fiddle leaf fig.

How To Get Rid of Mealybugs on Succulents

You’ll see advice online to spray succulents with straight rubbing alcohol, or even pour it on the soil as a drench. Extension guidance doesn’t recommend that. The limit is 70% or less, dabbed on with a swab after a test on a small part of the plant, and 10-25% for a spray, and alcohol is also listed as phytotoxic and should not be applied to plant tissues.

For succulents, Iowa State University Extension says to look for cottony masses along leaf veins and where leaves and stems join, isolate the plant, rinse the foliage and physically remove the masses. It says neem and insecticidal soap can be used as instructed on the label, that most infestations take multiple applications, and that a severe infestation that can’t be controlled means discarding the plant to protect nearby plants.

Look below the soil line, too. Small white cottony masses around the drainage holes of a pot point to root mealybugs, which often can only be confirmed by sliding the root ball out. Ground mealybugs are even more difficult to control than those feeding above ground, so dispose of infested plants quickly before the pests move to clean ones. For more, read our guide to mealybugs on succulents and what the fuzzy white bugs on plants are.

If you grow succulents outdoors, encourage natural predators such as lady bugs, which are among the natural enemies of mealybugs.

Keep a Clean Plant Area

Mealybugs hide in the gear around your plants as well as on them. Check pots, stakes and other materials for mealybugs and their egg sacs and dispose of infested items. Consider tossing older “grandmother” plants that may be a source of infestation for new plants.

Check the bottoms of containers and saucers when you inspect, and keep infested plants from touching others: mealybugs can easily crawl from one plant to another where leaves or branches overlap.

Vigilance Is Key

Catch mealybugs before they have a chance to build up, and the gentle methods have their best shot. Washing rarely gets every mealybug, so check plants periodically and treat again when more show up. Keep looking under leaves, in leaf joints and around new growth every time you water.

Got a mealybug fix that worked for you? Tell us in the comments.

Recommended Reading

• Are Mealybugs Harmful To Humans?
• 6 Home Remedies For Controlling Mealybugs