Which bugs are on my monstera’s new growth and leaf undersides?
Monstera has few pests indoors, says University of Wisconsin-Madison Extension. Aphids, mealybugs, scale insects or spider mites may infest it. Check new growth, leaf undersides and leaf axils first. Small dark flies over the soil are most likely fungus gnats, which prefer moist soil. Try water and hand removal before any product.
Updated
Which bug is on my monstera?
Monstera may host aphids, mealybugs, scale insects and spider mites. Each one leaves a different clue. Wisconsin Extension says the plant has few pests indoors, so a new bug deserves a close look. Check leaf undersides, stems and leaf axils in good light.
The table below draws on Iowa State, UConn and Colorado State. For more detail, see the guides to mealybugs and spider mites.
| What you notice | What to check | A useful next step |
|---|---|---|
| White, cottony clusters in leaf axils or under leaves | Likely mealybugs. Iowa State says these white, cottony insects are often found in leaf axils and on leaf undersides. | Isolate the plant. UConn says you can crush the insects by hand or wipe them off with a Q-tip. |
| Fine white spots or yellow-green mottling on leaves | Possibly spider mites. UConn says they drain chlorophyll and leave fine white spots called stippling. Iowa State says to tap a leaf over paper and look for tiny specks that move. | Iowa State says to rinse the foliage thoroughly in a shower or outdoors. |
| Small brown or beige bumps on stems and leaf veins | Possibly scale insects. Iowa State says they look like small bumps in clusters or lines along stems and leaf veins, typically on the underside. | Colorado State says light infestations can be killed by rubbing or picking the scales off. |
| Insect clusters on new growth | Possibly aphids. UConn says new growth on monstera is most susceptible. Iowa State says aphids cluster on growing points and under leaves. | For light infestations, Iowa State says a forceful spray of water can dislodge most aphids. |
| Small dark flies jumping or flying over the soil | Likely fungus gnats. Colorado State says adults are commonly seen around windows. | Let the soil surface dry between waterings, as the fungus gnat section below explains. |
If two clues overlap, take a clear photo of a leaf underside and the stem. The guide to photographing a sick plant covers the basics. Photos help when you ask a nursery or extension office.
Plant Doctor, an AI plant diagnosis app for iPhone, reads three photos and names the most likely cause along with the evidence behind it.
What should I do first when I find bugs on my monstera?
Move the monstera away from your other plants. Then look closely at all of them. Iowa State says to isolate infested plants so the pests don’t spread to other houseplants.
- Isolate. Keep the monstera apart from other houseplants until the bugs are gone.
- Look often. Colorado State says to monitor houseplants frequently and deal with pests early, while populations are small.
- Trace the source. Colorado State says scale, mealybug and whitefly infestations are almost always established from infested plants recently bought or received as gifts. Iowa State says to inspect new plants carefully and never bring in plants that have infestations.
- Check the plant’s health. Colorado State says plants that are not growing vigorously or are under stress may be more susceptible to insect and mite injury. Review your watering with signs that a plant needs water.
What can I try on my monstera before any product?
Start with water and your hands.
- Wash the leaves. Colorado State says washing a plant now and then with a vigorous jet of water can control many houseplant pests, at least in part. It says this works especially well on spider mites and aphids.
- Pick off larger insects. Colorado State says hand picking is especially useful for scale insects and mealybugs. For a few mealybugs, Iowa State says to spot treat with a cotton swab dipped in rubbing alcohol.
- Raise humidity for mites. Iowa State says spider mites prefer dry conditions, so more humidity can slow their population growth. Wisconsin Extension says monstera prefers medium to high humidity.
- Fix the setting. Colorado State says plants in very hot, dry sites are prone to spider mites. It also says a poor growing environment can make spider mite problems worse.
When should I use a product on my monstera bugs?
Use a product only if the bugs stay after washing and hand removal. Follow the product label, and choose a product labeled for houseplants.
UConn says to isolate or discard infested plants. It says mealybugs can be treated with an insecticidal soap registered for houseplant use. Iowa State says insecticidal soap, neem and pyrethrin can be used indoors on mealybugs. It says to apply them often, because they work best on the immature insects. UConn also says spider mites can be washed off with water or insecticidal soap. Pay special attention to leaf undersides.
Iowa State says insecticides are frequently ineffective on fungus gnats. The larvae live in the soil, and the adults are too mobile to spray. Colorado State says larval control works better. It says the biological insecticide Bacillus thuringiensis var. israelensis is highly effective as a soil drench.
Colorado State advises against treating plants that suffer from temperature extremes or drought with pesticides. This limits the chance of plant injury. It also says seriously infested plants are often best thrown out. They usually take lengthy effort to control and can infest other plants. For severe or unclear cases, ask a local nursery or your extension service.
Are small flies over my monstera’s soil a watering problem?
Small dark flies over the soil are most likely fungus gnats, and they prefer moist soil. Iowa State says that makes them good indicators of over-watering.
Colorado State says to limit watering so the soil surface can dry between waterings. UConn says monstera should be watered after the top 2-3 inches of soil have dried.
Iowa State also says never to let plants sit in saucers or outer pots filled with water. It says yellow sticky cards can catch flying adults but do not prevent new ones from hatching. For more on this pest, see fungus gnats.
Monstera questions
Do sticky leaves mean my monstera has bugs?
They can. Iowa State says mealybugs make honeydew that makes lower leaves and nearby surfaces sticky. Over time the deposits turn black with sooty mold. UConn says aphids and scale insects also make honeydew. See sticky leaves for more causes.
Can bugs live on my monstera’s roots?
Colorado State says mealybugs can infest roots as well as foliage. It says some species tend to move to roots when growing conditions are less favorable.
Will yellow sticky cards clear the bugs?
Not by themselves. Colorado State says yellow sticky traps reduce flying pests such as whiteflies, winged aphids and fungus gnats. It says trapping alone will not eliminate problems, because the younger stages stay on or around the plants.
Can spider mites make monstera leaves fall off?
Iowa State says the yellow-green mottling turns tan as spider mite infestations worsen. It says leaves eventually fall off.
Sources and further reading
Care guidance checked against the sources below. Plant Doctor’s app examples are separate from these references; the institutions do not endorse the app.
- UConn Home and Garden Education Center — Monstera deliciosa | Home Garden Education Office | College of Agriculture, Health and Natural Resources | University of Connecticut
- University of Wisconsin-Madison Extension — Swiss-Cheese Plant, Monstera deliciosa
- Iowa State University Extension and Outreach — Diagnosing Houseplant Problems Caused by Insect Pests
- Colorado State University Extension — Managing Houseplant Pests
Drafted with AI from the sources below; each plant-specific fact checked automatically against its source on 26 October 2026.
This guide offers general plant-care information. A photo cannot confirm every cause; a local nursery or extension service can help with severe or unclear cases.