Common Houseplant Pests: How to Identify Spider Mites, Mealybugs, Thrips, Scale & Fungus Gnats

Quick answer: The most common indoor plant pests include spider mites, mealybugs, thrips, scale insects, and fungus gnats. The best first step is to isolate the affected plant, inspect it closely, identify the pest, and then choose a treatment that matches the pest and plant.

How to inspect a houseplant for pests

Look at more than the top of the leaves. Many pests hide on leaf undersides, along stems, around new growth, where leaves meet the stem, or in the upper layer of potting mix.

• Use bright light.
• Check both sides of leaves.
• Look closely at new growth.
• Inspect sticky, webbed, distorted, speckled, or discolored areas.
• Check nearby plants because pests can spread.

Spider mites

Spider mites are tiny sap-feeding pests. They are often noticed because of fine webbing, pale stippling, dusty-looking foliage, or rapid decline on susceptible plants.

Common signs of spider mites

• Fine webbing between leaves or stems
• Many tiny pale dots on leaves
• Dry, faded, or bronzed foliage
• Small moving specks on leaf undersides

Mealybugs

Mealybugs often appear as white, cottony clusters around stems, leaf joints, and new growth. They feed on plant sap and may produce sticky honeydew.

Common signs of mealybugs

• White cotton-like masses
• Sticky residue
• Stunted or distorted growth
• Clusters around nodes and leaf axils

Thrips

Thrips are slender insects that scrape and feed on plant tissue. Damage can look silvery, streaked, scarred, or distorted, especially on young leaves.

Common signs of thrips

• Silvery or bronze patches
• Black specks of waste
• Distorted new growth
• Scarring on leaves

Scale insects

Scale insects often look like small brown, tan, or pale bumps attached to stems or leaves. Because they can look like part of the plant, they are easy to miss.

Common signs of scale

• Firm bumps on stems or leaf surfaces
• Sticky honeydew
• Yellowing leaves
• Weak or declining growth

Fungus gnats

Adult fungus gnats are small dark flies that hover around moist potting mix. Their larvae live in the soil. A persistent infestation often points to potting mix that is staying wet for long periods.

Common signs of fungus gnats

• Tiny dark flies near the soil
• Adults flying up when the pot is moved
• Persistently wet potting mix

What to do when you find pests

1. Isolate the plant. Move it away from the rest of your collection.
2. Identify the pest. Treatment works better when you know what you are dealing with.
3. Remove heavily damaged material if appropriate.
4. Clean leaves and stems. Physical removal can reduce the population before treatment.
5. Use a treatment labeled for the pest and plant. Follow all product directions exactly.
6. Repeat inspections. One treatment may not eliminate every life stage.

Can overwatering cause plant pests?

Overwatering does not directly create all pests, but consistently wet soil strongly favors fungus gnats and can weaken roots. Review our houseplant watering guide if your potting mix stays wet for long periods.

Houseplant pest FAQ

Should I throw away a plant with pests?

Not necessarily. Many infestations can be managed, especially when caught early. Severe infestations may require more effort and isolation.

Can pests spread from one plant to another?

Yes. Several common houseplant pests can move between nearby plants, which is why isolation and inspection matter.

Why do pests keep coming back?

Eggs or hidden life stages can survive an initial treatment. Repeated inspection and treatment according to the product label may be necessary.

If your plant is also yellowing, use our yellow leaves troubleshooting guide to compare other possible causes.