Monstera Pests: The Complete Identification and Treatment Guide

Scale insects, spider mites, thrips, fungus gnats, mealybugs, and aphids: how to tell them apart, treat each one without chemicals, and stop them coming back.

Monsteras are some of the hardiest plants you can bring into your home. Given enough water, light, and nutrients, they thrive and reward you with those striking, fenestrated leaves.

But neglect a Monstera, or love it a little too hard, and it will start showing signs of distress: yellowing leaves, stunted growth, unexplained holes, sticky residue, or leaves that come in smaller than they should.

More often than not, the root cause is a pest infestation, and pests take hold precisely because of the neglect or overcare that came before them.

This guide covers the six pests most likely to affect your Monstera, how to identify each one with confidence (including the ones that get confused with each other), and exactly how to treat and prevent them without reaching for harsh chemicals.

Monstera Pests at a Glance

Use this table to narrow down what you’re dealing with, then jump to the relevant section for full identification and treatment detail.

Pest Lookalikes: How to Tell Them Apart

Several of these pests get confused with each other, and misidentifying one delays effective treatment.

Mealybugs and woolly aphids both look cottony; scale insects and mealybugs both feed in the same spots; whiteflies (which can also turn up on Monstera, though less often than the six above) get mistaken for gnats. Use this table to settle it quickly.

The 6 Most Common Monstera Pests

Pests rarely settle onto a Monstera, or any houseplant, that has everything it needs.

They move in when there’s a loophole: too much humidity, overwatering, or poor air circulation creates the exact conditions they thrive in.

We’ll cover those root causes in detail further down, but first, here’s how to identify and treat each pest in full.

1. Scale Insects

More than 1,000 species of scale insect exist in North America alone, so your Monstera is never entirely out of reach of one.

These insects feed on your Monstera’s sap, starting as a small, easy-to-miss infestation that grows steadily because the insects themselves are immobile once settled.

As the population builds, the plant spends so much energy healing infested leaves that it stops producing new growth.

Leaves take on a yellow hue as chlorosis sets in, and left unchecked, a heavy infestation can eventually kill the plant.

Scale insects reproduce quickly: adult females lay eggs under a protective covering that hatch within a month, and the resulting nymphs disperse to find their own feeding spot.

Because there’s no pupal stage, new nymphs appear every month, and females can lay eggs without mating at all.

How to Identify Scale Insects

Look for two types. Armored scale insects have a hard covering that isn’t actually attached to their body, it’s a secreted shell they hide under while feeding.

They don’t move and don’t produce honeydew, so your focus should be on immobile bumps with a hard surface.

Soft scale insects have a waxy surface instead, and unlike the armored type, they secrete honeydew and can move slightly across the plant.

How to Get Rid of Scale Insects

1. Prune affected parts: If the infestation covers a large section, wear gloves and prune it away with a sharp, sterile tool, sterilising between each cut. Dispose of the cuttings well away from other plants.
2. Pick them off by hand: For small infestations, use gloves and a magnifying glass to remove insects individually. Expect to repeat this over a few sessions, since unnoticed eggs will keep hatching.
3. Use alcohol or neem oil: Soak a cotton ball and rub it directly onto affected areas. This weakens the pests and breaks down their protective coverings.
4. Introduce natural predators: Ladybugs and lacewings feed on scale insect nymphs in the wild, and adding them to your Monstera can replicate that effect for smaller infestations.
5. Apply organic pesticides: Insecticidal soap kills nymphs but usually needs several applications to fully control an infestation.
6. Use botanical insecticides for severe cases: These are gentler than synthetic pesticides but still effective, and should be used cautiously and only when the population is too large for the methods above.

If ants are present around an infested Monstera, deal with them too. Ants farm scale insects for their honeydew and will actively defend them, which undermines any natural predators you introduce.

2. Spider Mites

Fine webbing on your Monstera is the clearest giveaway of spider mites, arachnids rather than insects, that feed on plant sap and spin silk as they spread.

Because they travel via their own webs, hitch rides on people, or drift on air currents, an infestation rarely stays confined to one plant for long.

If you find spider mites on your Monstera, check every other plant nearby. Their mobility is exactly what makes them such a persistent problem.

Spider mites overwinter as eggs, then hatch into larvae once temperatures rise, feeding for a few days before moving through three nymphal stages on the way to adulthood.

That whole cycle can take as little as a week, and mature females lay around 300 eggs every few weeks, so populations can reach the tens of thousands within a couple of months.

The damage is disproportionate to their size. Feeding robs the plant of sap, breaks down its natural leaf defences, and leaves it more exposed to disease, which typically shows up as yellowing leaves with small brown feeding spots.

How to Identify Spider Mites

A magnifying glass is essential here. Check the underside of leaves for webbing, since most mite activity happens underneath it. Light stippling or dotting on the leaf surface is another giveaway.

Adult mites are reddish-brown or black, oval, and only around 1/50 inch long, easy to miss without close inspection.

If you find webbing, hold a sheet of white paper under the leaf and shake it gently; any mites present will fall onto the paper and be far easier to spot against the contrasting background.

How to Get Rid of Spider Mites

• Prune the affected parts: Use a sharp, sterilised blade. If the infestation covers most of the plant, it may be more practical to propagate a healthy cutting and discard the rest.
• Hose the plant down: A strong, direct stream of water dislodges a large share of the mites. Support the leaves as you do this to avoid tearing them, and follow up with one of the methods below.
• Add natural predators: Once numbers are reduced by pruning or hosing, predatory insects can mop up the rest and keep new hatchlings in check.
• Use an organic insecticide: These act on spider mites at every life stage, which makes them more reliable against mixed-age populations.
• Apply neem oil: A natural repellent that won’t clear an infestation in one application but reduces numbers steadily with repeat use.
• Wash with insecticidal soap: Mix a cup of oil, a tablespoon of dish soap, and warm water, then spray directly onto the plant. Avoid this above 85°F (29°C), as the mixture can make leaves more prone to sunburn in strong light.
• Remove dust from the leaves: Dust build-up encourages spider mite activity, so wiping leaves down periodically helps prevent future infestations, alongside keeping the plant adequately watered, since hot, dry conditions are exactly what mites favour.

Chemical pesticides are deliberately left off this list. Spider mites have natural predators that keep populations in check, and broad-spectrum pesticides wipe those predators out too.

Worse, spider mites adapt to chemical treatments quickly, which can make repeat infestations harder to control over time.

For general care that keeps your plant resilient against pests like this, see our guide on how to care for a Monstera.

3. Thrips

At least 5,000 species of thrips exist, and they damage Monstera plants in two distinct ways.

First, they feed on the moisture in leaves, leaving them dry, brown, and unable to photosynthesize properly; a heavily affected plant looks pale and weak, and won’t recover if the damage is extensive.

Second, thrips can spread plant viruses, adding a second layer of stress to an already weakened plant.

Thrips feed in large groups, moving efficiently from leaf to leaf, which is part of why an untreated infestation can escalate so quickly.

Their lifecycle starts with adults and pupae overwintering, then females laying up to 80 eggs (no mating required) once the weather warms.

Eggs hatch within days, and the nymphs move through three nymphal stages before dropping into the potting soil to pupate.

In good conditions, egg to adult can take as little as two weeks, so numbers escalate fast.

How to Identify Thrips

Adults measure around 1/25 inch, straw-coloured or black, with two pairs of wings, and they tend to fly off the moment they’re disturbed, making them hard to catch with a magnifying glass.

Focus instead on the larvae, which feed in visible clusters that look like tiny white balls on the undersides of leaves. Browning and curling on the leaves themselves are additional warning signs.

How to Get Rid of Thrips

• Isolate the plant: Move an affected Monstera away from other plants for around two weeks while you treat it. It’s also worth quarantining any new plant for the same period before introducing it to your collection.
• Prune the plant: Cut away heavily affected sections with a sharp, sterile tool. Because thrips cluster together, pruning removes a large share of the population in one move.
• Hose the plant down, in isolation: Direct a strong stream of water at the underside of the leaves to knock larvae off, ideally away from other plants so you don’t spread the infestation further.
• Apply neem oil or insecticidal soap: Both are effective against thrips that survive the physical methods above. Neem oil is safe around pets and beneficial insects and disrupts the pest’s lifecycle rather than killing on contact.
• Add natural predators: Minute pirate bugs, ladybugs, and lacewings all feed on thrips at different life stages, and work best once the population has already been reduced physically.

To stop thrips re-establishing, remove any loose plant debris from the potting soil surface, since it gives them cover, and build a regular inspection habit.

Check the undersides of leaves each time you water, and step in with the measures above the moment you spot the tell-tale white clusters.

A more detailed, thrips-specific treatment walkthrough is coming soon on our dedicated thrips guide.

4. Fungus Gnats

Fungus gnats are often mistaken for mosquitoes hovering near a window rather than something to worry about on the plant itself, but that assumption misses the real risk.

Adult fungus gnats lay their eggs in your Monstera’s potting soil, and it’s the resulting larvae that cause the damage, feeding directly on the plant’s roots.

Root damage reduces the plant’s ability to absorb water and nutrients, which shows up as slow or stunted growth, yellowing leaves from chlorosis, and eventually wilting as the plant loses the turgor pressure that keeps its leaves upright.

Each adult lives around a week and lays roughly 300 eggs in that time.

Larvae hatch within days and feed on roots through a short pupal stage before emerging as adults themselves, a full cycle in as little as three weeks.

That rapid turnover is what makes fungus gnats so hard to fully eliminate once established.

How to Identify Fungus Gnats

Adults resemble small mosquitoes, with long legs and transparent wings in grey or black tones.

They’re weak fliers, hopping short distances near the plant rather than roaming far, and typically scatter when you approach or water the plant, only to return once you’ve left.

Unlike fruit flies, they won’t cluster around bins or fruit, which is a useful way to tell the two apart.

How to Get Rid of Fungus Gnats

• Let the soil dry out: Overwatering creates the damp, fungus-rich conditions that attract egg-laying adults. Allowing the top inch or two of soil to dry between waterings disrupts their breeding cycle directly.
• Water from the bottom: Bottom watering keeps the soil surface drier, denying fungus gnats the moist top layer they need to lay eggs.
• Add a dry topdressing: A layer of sand or fine gravel on the soil surface acts as a physical barrier, making it harder for adults to reach the soil and lay eggs.
• Use yellow sticky traps: These capture adult gnats effectively and double as an early-warning system for population size.
• Apply beneficial nematodes to the soil: These microscopic worms target fungus gnat larvae directly, releasing bacteria that kill them from within.

Changing your watering habits is the single most effective long-term fix here, since it removes the damp breeding ground fungus gnats depend on rather than just treating symptoms as they appear.

If overwatering is a recurring issue, our Monstera watering schedule will help you dial in a routine that suits your home.

5. Mealybugs

Mealybugs are one of the most common pests on tropical houseplants, and Monstera is no exception.

They’re small, soft-bodied insects covered in a white, cottony wax that most people initially mistake for mould or plant debris rather than a living pest.

You’ll usually find them wedged into leaf axils, along stems, and on the underside of leaves, exactly the sheltered spots where a shell-less insect can feed undisturbed.

Like scale insects, mealybugs feed on sap through piercing mouthparts and excrete sticky honeydew as they do.

Left untreated, that honeydew coats the plant and encourages black sooty mould, while the feeding itself causes yellowing, stunted growth, and dieback in heavily affected sections.

Females lay 300 to 600 eggs in cottony sacs attached to stems or leaf joints, and the eggs hatch into crawlers within seven to ten days.

A full lifecycle takes six weeks to two months depending on conditions, and because breeding continues year-round indoors, a small, missed colony can rebuild a population you thought you’d cleared.

How to Identify Mealybugs

Look for white, cottony masses clustered at leaf joints, along stems, and on leaf undersides.

Unlike scale insects, mealybugs are soft-bodied underneath their waxy coating, and wiping one away reveals an oval, segmented body rather than a hard shell.

Sticky honeydew on nearby leaves or on surfaces below the plant is a strong secondary sign, as is the presence of ants, which farm mealybugs for the honeydew they produce.

Check outside the pot as well as on the plant itself. Mealybugs commonly nest under pot rims, around drainage holes, and on the underside of saucers, spots that are easy to miss during a routine leaf inspection and a common reason treatments fail to fully clear an infestation.

How to Get Rid of Mealybugs

• Isolate the plant: Move it away from other houseplants immediately, since mealybugs spread readily to anything touching or standing near an infested plant.
• Spot-treat with rubbing alcohol: For light infestations, dip a cotton swab in 70% isopropyl alcohol and dab each visible mealybug directly. The alcohol dissolves their waxy coating and kills them on contact. Test on a small leaf area first, since alcohol can damage some foliage.
• Wash the whole plant: Rinse the plant thoroughly under a strong stream of water, targeting leaf undersides, joints, and stems, to physically remove pests, egg sacs, and debris.
• Apply insecticidal soap for heavier infestations: Spray thoroughly, ensuring coverage in leaf axils and stem joints. Multiple applications spaced a week apart are usually needed, since eggs hatch in waves.
• Check the roots on severe or recurring cases: If mealybugs keep returning despite treating the visible plant, unpot it and check for root mealybugs, which leave a white residue around the root ball. Rinse the roots, flush with a diluted hydrogen peroxide solution, and repot in fresh mix.
• Clean the pot and saucer: Wash both in hot, soapy water, particularly unglazed terracotta, which mealybugs readily colonise on the underside.

Mealybugs are widely considered one of the more difficult houseplant pests to fully eliminate, largely because they hide so effectively.

Plan on monitoring the plant at every watering for several weeks after treatment, and don’t consider the infestation cleared until you’ve gone two full weeks without spotting a new colony.

6. Aphids

Aphids are small, soft-bodied, pear-shaped insects that cluster on tender new growth, exactly the parts of a Monstera with the softest tissue and easiest sap access.

They vary widely in colour, appearing green, black, brown, yellow, or occasionally with a woolly white coating, which sometimes leads to confusion with mealybugs.

Feeding causes curling, distorted new leaves and a general weakening of the plant, and like mealybugs and scale insects, aphids excrete honeydew that leads to sticky residue and sooty mould if left unaddressed.

Heavier infestations can stunt new growth almost entirely, since the newest leaves are where aphids concentrate.

Most indoor aphid populations reproduce asexually, with females giving birth to live nymphs without mating, and nymphs reach adulthood in as little as five to seven days.

Because immature aphids shed their exoskeletons as they grow, you’ll often notice small white flecks on leaves before you spot a live insect, an early warning sign worth checking for specifically.

How to Identify Aphids

Check new growth and flower buds first, since aphids favour the softest, most nutrient-rich tissue on the plant.

Look for small, pear-shaped insects, often clustered together rather than scattered individually.

Curling or distorted new leaves, sticky honeydew, and tiny pale flecks (shed nymph skins) on the leaf surface are all supporting evidence even if you haven’t spotted a live insect yet.

Aphids are easy to confuse with young mealybugs or immature scale insects at a glance.

The clearest distinguishing feature is shape: aphids are distinctly pear-shaped with visible legs and antennae, while mealybugs are more oval and stay wedged into joints rather than moving across open leaf surfaces.

How to Get Rid of Aphids

• Hose the plant down: A firm spray of water dislodges the majority of an aphid colony quickly and is often enough on its own for light infestations.
• Wash with insecticidal soap: Mix a mild dish soap with water and spray thoroughly, focusing on new growth and the undersides of leaves where aphids cluster.
• Apply neem oil: Effective against aphids at every life stage and safe to use repeatedly as a preventative measure once the initial infestation clears.
• Introduce natural predators: Ladybugs and lacewing larvae are highly effective aphid predators and work well once the population has already been reduced by hosing or spraying.
• Prune heavily infested new growth: If a particular shoot or leaf cluster is severely affected, removing it entirely is often faster than trying to treat it in place.

Aphids respond to treatment more readily than most other pests on this list, since every life stage, from nymph to adult, is vulnerable to the same control methods at the same time.

Consistent, repeated treatment over one to two weeks is usually enough to clear an infestation fully.

If new leaves are coming in smaller or slower after an aphid infestation, our guide on encouraging a Monstera to grow more leaves covers recovery steps.

What Causes Pest Infestations in the First Place?

A healthy Monstera with a strong immune system rarely attracts pests unprompted.

Infestations tend to follow one of three underlying issues, each of which weakens the plant’s natural defences and creates ideal breeding conditions.

Too Much Humidity

Monsteras enjoy humidity above 70%, but there’s a ceiling. Without adequate airflow to match it, the plant sits in stagnant, moisture-laden air, which is exactly the environment most pests thrive in.

Aim to keep humidity between 70% and 80% while ensuring the space stays ventilated.

For the specifics, see our guide on the ideal humidity for a Monstera and how to mist a Monstera for humidity without overdoing it.

Overwatering

Overwatering weakens roots by depriving them of oxygen, and roots left sitting in waterlogged soil are prone to fungal disease.

Once disease takes hold at the base of the plant, its overall ability to resist pests attacking from above drops significantly.

If you suspect this is already happening, our guide on fixing root rot in a Monstera covers the recovery process in full.

Poor Ventilation

Humidity becomes a bigger problem specifically when air circulation is limited.

Without movement, the plant loses less water to its surroundings, leaving it sitting in damp soil surrounded by still, humid air, a combination that reliably invites pests.

Give the plant enough breathing room by relocating it to an airier spot or pruning back excess growth that’s crowding the space around it.

Our guide on how to prune a Monstera covers exactly where and how to cut back growth safely.

Bringing Infested Plants Indoors

Any new plant, and any Monstera that has spent time outside over summer, is a common entry point for pests that have no natural predators to keep them in check indoors.

Inspect every new plant closely, including the underside of the pot and saucer, and quarantine it away from your existing collection for two weeks before introducing it properly.

If your Monstera has been outside recently, see our guide on bringing a Monstera outside in summer for what to check before moving it back in.

If any of this sounds familiar, don’t worry. These are all fixable habits, and correcting them is the single best long-term defence against every pest covered in this guide.

Quick Diagnosis: Matching Symptoms to the Right Pest

Several Monstera problems overlap across pests and general care issues. Use this table to cross-check what you’re seeing before you start treatment.

For yellowing not linked to pests, see our guide on why Monstera leaves turn yellow. If leaves are curling, why your Monstera leaves are curling covers non-pest causes in more detail.

A Simple Pest Prevention Routine

Treating an infestation is always more work than preventing one. This routine takes a few minutes a week and addresses the root causes behind every pest in this guide.

• Inspect at every watering: Check leaf undersides, joints, and the soil surface each time you water, since this is when you’re already handling the plant closely.
• Quarantine new plants: Keep any new arrival, and any plant returning from time outdoors, isolated for two weeks before it joins your main collection.
• Wipe leaves periodically: A damp cloth removes dust and disrupts pests like spider mites before they establish, and it’s a good moment to check for early signs of trouble.
• Keep watering consistent: Both overwatering and underwatering stress the plant in ways that make it more vulnerable, so aim for a routine rather than reacting to how the plant looks day to day.
• Maintain airflow: A small fan or simply avoiding overcrowding your plant shelf reduces the stagnant, humid conditions most pests rely on.
• Apply neem oil preventatively: A light monthly application, even with no visible pest activity, deters most of the pests covered in this guide before they take hold.

For the full toxicity breakdown, see our guide on whether Monstera is toxic to you and your pets.

Frequently Asked Questions

What is eating holes in my Monstera leaves?

Natural fenestrations are normal on mature Monstera leaves and appear as clean, symmetrical splits or oval holes.

Irregular, ragged holes or chewed edges are more likely pest damage, most commonly from thrips, or less often from larger outdoor pests if the plant has spent time outside.

If you’re unsure whether your plant is fenestrating normally, see our guide on why Monstera leaves aren’t splitting.

What’s the difference between mealybugs and scale insects?

Both feed in similar spots and produce similar chlorosis symptoms, but their appearance differs clearly on close inspection.

Mealybugs are soft-bodied and covered in loose, cottony wax that comes away when disturbed. Scale insects have a hard, fixed shell that doesn’t move or wipe off in the same way.

If you’re not sure which you’re looking at, try gently scraping the bump: a mealybug’s waxy coating smears, while a scale insect’s shell stays intact.

Can I use dish soap instead of insecticidal soap?

A homemade mix of mild dish soap, oil, and water can work in a pinch and is referenced throughout this guide for spider mites, aphids, and thrips.

Use a small, unscented, dye-free liquid soap, test it on one leaf first, and avoid applying it in direct sun or high heat, since it can increase the risk of leaf scorch.

If your plant has already been affected by strong light exposure, see our guide on saving a Monstera with sunburn.

How long does it take to get rid of Monstera pests completely?

Most infestations take two to six weeks to fully clear, depending on the pest and how early you catch it.

Spider mites and thrips typically need repeat treatments every five to seven days to catch newly hatched generations.

Mealybugs are among the slowest to fully clear, often three to six weeks, because eggs hatch in waves and colonies hide in hard-to-reach spots.

Aphids usually respond fastest, often within one to two weeks, since every life stage is vulnerable to treatment at once.

Should I isolate my Monstera if I find pests?

Yes, for every pest covered in this guide. Spider mites, thrips, aphids, and winged mealybug males all spread readily to nearby plants, and even less mobile pests like scale insects and immature mealybugs can spread slowly through leaf contact.

Isolating the plant during treatment is good practice across the board.

Will pests come back after treatment?

They can, particularly if the underlying cause, overwatering, excess humidity, or poor airflow, isn’t addressed.

Treating the pest without correcting the growing conditions that invited it usually leads to a repeat infestation within a few months.

Mealybugs and scale insects are especially prone to returning if any hidden colony under a pot rim or in a leaf joint goes unnoticed.

Are these pests specific to Monstera, or do they affect other houseplants too?

All six pests covered here are generalists that affect a wide range of houseplants, not just Monstera.

If you have other tropical plants nearby, check them at the same time you inspect your Monstera, since an infestation rarely stays confined to a single plant for long.

Can I prevent pests without using any chemicals?

Yes. Consistent watering habits, good airflow, and periodically wiping leaves down with plain water go a long way toward preventing all six pests on this list.

Neem oil, used preventatively every few weeks, is also a widely used natural deterrent that doesn’t rely on synthetic chemicals.

Why do pests keep coming back even after I treat them?

The most common reason is an incomplete treatment rather than a new infestation.

Eggs that survive the first treatment hatch later, hidden colonies under pot rims or in leaf joints get missed, or the underlying condition, usually overwatering or low airflow, was never corrected.

Repeat treatments on a schedule, rather than stopping as soon as visible pests disappear, is the most reliable way to break the cycle.

Key Takeaways

• The six most common Monstera pests are scale insects, spider mites, thrips, fungus gnats, mealybugs, and aphids, each identifiable by distinct visible signs.
• Mealybugs and scale insects look similar but differ clearly on close inspection: mealybugs are soft and cottony, scale insects are hard-shelled and fixed in place.
• A magnifying glass is essential for accurate identification, since most of these pests are difficult or impossible to spot reliably with the naked eye.
• Pruning, hosing down, and neem oil or insecticidal soap treat most infestations without resorting to synthetic pesticides.
• Overwatering, excess humidity without airflow, and poor ventilation are the root causes behind almost every pest infestation.
• Isolating an affected plant for two weeks prevents mobile pests from spreading to your wider collection.
• Check outside the pot too. Mealybugs in particular often hide under rims and saucers, which is why treatments that only address the visible plant sometimes fail.
• Fixing the underlying growing conditions, not just treating the pest, is what stops infestations from coming back.

A Note on Sources

Identification and treatment guidance in this article were checked against horticultural extension research, including the University of Minnesota Extension’s houseplant pest guidance and the

University of Maryland Extension’s guidance on mealybugs, both of which cover identification and treatment thresholds for common indoor plant pests.

What’s Next

Once your Monstera is pest-free, the best next step is tightening up the care routine that keeps infestations from returning.

Start with watering and humidity, then check your plant’s overall health against common problem signs.

Start here: how to revive a dying Monstera, or explore our full Monstera care guide for everything else.