What’s on my plant?

Look at where the bug is and what the leaf looks like: flies around the soil are fungus gnats, pale dots and webbing under leaves are spider mites, white cotton in the leaf joints is mealybugs, brown bumps on stems are scale, green clusters on new growth are aphids, and silvery streaks with black specks are thrips.

Most of these can be handled at home with a shower, a cotton swab and insecticidal soap — if you catch them early and repeat the treatment.

Quick chart

What you see	Where	Pest	First step
Small dark flies, weak fliers	Around the soil, on windows	Fungus gnats	Let the top 2 inches of soil dry
Pale dots, fine webbing	Under leaves	Spider mites	Rinse the plant in the shower
White cotton clumps	Leaf joints, under leaves, roots	Mealybugs	Dab with rubbing alcohol on a swab
Brown or tan bumps that don’t move	Stems and leaf veins	Scale	Scrape off, then treat
Green/black pear-shaped bugs in groups	Tips and new leaves	Aphids	Spray off with water
Silvery streaks, black specks	Leaf surfaces, flowers	Thrips	Rinse, then soap weekly
Sticky, shiny leaves	Leaves and the floor below	Honeydew from aphids, scale or mealybugs	Find the bug above it

Fungus gnats

The most common indoor pest and the least harmful: adults are just annoying, larvae live in wet topsoil. They’re a sign the soil stays too wet. Full plan: how to get rid of fungus gnats.

Spider mites

Barely visible, but the damage isn’t: a leaf that looks sprinkled with salt, then dull and bronze. They love warm, dry rooms, so they peak when the heating is on. Tap a leaf over white paper; moving specks confirm it. 3-week treatment plan →

Mealybugs and scale

Both suck sap and leave sticky honeydew. Mealybugs look like bits of cotton and hide in leaf joints and even on roots. Scale looks like little brown shells glued to stems — many people mistake them for part of the plant until they scrape one off.

What works at home:

1. Isolate the plant.
2. Mealybugs: touch each one with a cotton swab dipped in 70% rubbing alcohol. Scale: scrape them off with a fingernail or an old toothbrush.
3. Spray the whole plant with insecticidal soap or horticultural oil labeled for houseplants, covering leaf undersides and stems.
4. Repeat every 7 days for at least 4 weeks — young “crawlers” keep hatching from hidden eggs.
5. Heavily infested and not a favorite? Sometimes discarding the plant is the kindest option for the rest of your collection.

Aphids and thrips

Aphids cluster on soft new growth and flower buds. They’re easy: a strong spray of water knocks most off, and insecticidal soap finishes them. They often arrive on plants that spent summer outside.

Thrips are slender and fast, and you’ll more often see their damage — silvery, scratched-looking streaks with tiny black specks — than the insects. Treat like mites: rinse, then insecticidal soap weekly for 3–4 weeks, and remove damaged flowers where they hide.

Sticky leaves?

Shiny, sticky drops on leaves or on the furniture below mean sap-suckers are feeding above. Over time a black film (sooty mold) grows on the honeydew; it wipes off with a damp cloth once the pests are gone.

Prevention that actually works

• Quarantine new plants for 2 weeks before they join the others.
• Check leaf undersides when you water. Ten bugs are easy; ten thousand aren’t.
• Shower your plants every month or two to rinse off dust and early pests.
• Inspect plants before bringing them in for winter. The checklist →
• Don’t overwater. Soggy soil invites gnats and weakens roots. Watering chart →