How to Identify and Treat Pests in Your Plants

What You Need To Know

• Common culprits: Identify six common houseplant pests including mealybugs, scale, spider mites, fungus gnats, thrips, and slugs by their unique appearance and damage patterns
• Treatment toolkit: Use neem oil, insecticidal soap, alcohol spot-treatment, and sticky traps to eliminate infestations effectively
• Prevention tips: Inspect plants weekly, proactively treat, and isolate infested plants to stop pests from spreading

It's a moment that every plant parent fears: spotting a bug on your beloved houseplant. Whether you've noticed tiny webs under leaves, sticky residue on stems, or little flies hovering around the soil, don't panic—pests are a normal part of plant parenthood and totally treatable. The key is catching them early and knowing exactly what you're dealing with. Plus, you'll find that some insects may actually be harmless or even beneficial, so learning to tell the difference between the good guys and bad guys is an essential skill for any plant parent!

Below, we're breaking down the most common houseplant pests you're likely to encounter, from sneaky mealybugs to microscopic spider mites. For each pest, you'll learn how to spot the signs, where they like to hide, and our tried-and-true treatment methods to eliminate them for good.

1. Mealybugs

If you notice an oval-shaped insect covered by waxy, white cotton-like filaments on your plant, it is most likely a mealybug. They can be found in different parts of the plant but are commonly found along stems, leaf axels and along the veins on the underside of the leaves.  

Spot-treat visible bugs with a cotton swab or cotton pad dipped in alcohol, then spray all of the foliage down with a neem oil solution or insecticidal soap. Examine your plants weekly for traces of re-infestation, and wipe down the areas around your plants. 

For our in-depth recommendations on treating mealybugs, check out our mealybugs guide here.

2. Scale

Scale are another oval-shaped pest that are enclosed in a shell-like covering if they have matured enough. They are typically brown in color but can also be black or white. 

Mostly found along leaf veins or on stems, a mature scale will need to be picked or scraped off your plant manually because contact sprays will not penetrate through the insect's shell. However, treating your plant with a systemic insecticide first can help make the manual remover easier! After you remove all scale, the plant can then be sprayed down with a neem oil solution or insecticidal soap to kill any larvae or eggs that haven't create an impenetrable shell yet.

For our in-depth recommendations on treating scale, check out our scale guide here.

3. Spider Mites

Spider mites are microscopic arachnids that are usually red or yellow in color. You can easily identify them by the silky webbing, grayish stippling, and white castings on the underside of the foliage. They usually congregate on new growth on plants and the underside of leaves.

Lowering temperatures and boosting humidity can help ward off or slow down their reproduction (they thrive in hot, dry air!), but spray treatments should begin at the first sign of spider mites. Use an insecticide that lists “spider mites” on the label to target pests and spray down the plant. Treat your plant after 3 days, and again in 10 days. 

For our in-depth recommendations on treating spider mites, check out our spider mites guide here.

4. Fungus Gnat

Spotted tiny flies buzzing around your plant? You've probably got fungus gnats. These little guys are about 1/8 inch long, grayish-black, and honestly pretty weak fliers—they kind of just hover lazily around soil and lower leaves. They're often mistaken for fruit flies, but here's the tell: fungus gnats hang out near plants, while fruit flies go straight for your kitchen fruit bowl or sink. 

The adults are annoying but harmless. It's their babies (larvae) living in the soil that cause problems by munching on organic matter (fungus) and potentially damaging roots.

We recommend starting to set up yellow sticky traps to catch the adult gnats flying around which prevents them from laying more eggs. For the larvae hiding in soil, you've got options: sprinkle diatomaceous earth or mosquito bits on top of the soil, add BTI (Bacillus thuringiensis israelensis) drops to your watering routine, or repot your plant in fresh soil. Combining a few methods works best for total eviction!

For our in-depth recommendations on fungus gnats, check out our fungus gnats guide here.

5. Thrips

Meet thrips—elongated little pests that are about 1-2 mm long (think: smaller than a grain of rice) with brown or black bodies and sometimes feathery wings. Baby thrips are lighter in color, sometimes even greenish, which makes them tricky to spot.

They pierce plant cells and suck out the good stuff, leaving behind tell-tale damage. Your plant's leaves will look silvery or speckled, almost like someone scraped off the color with sandpaper. New growth might come in twisted, cupped, or distorted, and you may see brown, dying tissue in affected areas. If the infestation is bad, you'll notice tiny black dots on the leaves—that's thrip frass (sorry, but you needed to know).

First things first: quarantine your infested plant away from your collection to prevent thrips from spreading and apply a systemic treatment to the soil. Then, hit them with an insecticidal soap or neem oil spray, making sure to coat all leaf surfaces, especially undersides where thrips love to hide. Repeat treatments following the application rates on the brand you're using until they're gone for good.

6. Slugs

Wait, slugs? On my indoor plants? Yep, it happens—though thankfully it's pretty rare compared to other houseplant pests. These slimy little night owls are gray to brown and leave behind tell-tale shiny, mucus trails across the leaves and soil.

Check your leaves for ragged, irregular holes that look like something took bites out of them. The tricky part? Slugs are nocturnal, so they hide during the day—tucked under pots, in drainage trays, or burrowed in the soil. If you want to catch them, grab a flashlight and inspect your plants at night when they're actively munching.

If they're hiding in the soil, try flushing it thoroughly with water to drive them out. You can also hand-pick any slugs you spot and relocate them outside (or dispose of them—your call). For persistent problems, slug pellets or traps designed for houseplants work well. Just place them near affected plants and let them do the dirty work while you sleep.

Conclusion 

Look, dealing with plant pests isn't fun, but it's also not the end of the world (or your plants). Learning how to spot the signs, identify the culprits, and take action before things get out of hand will be key. Give your plants a quick once-over every week or so, and you'll catch any uninvited guests before they become a real problem. Your plants are tougher than you think, and so are you!