Skip to content
Pocket Botanist
Get the app

Alligator weed · Alternanthera philoxeroides

What are the bugs on my Alligator weed?

It is less common for this plant to suffer from pests, as its aquatic nature deters many common houseplant insects. When pests do appear, they are usually aphids or spider mites attracted by dry conditions.

Not sure it's this? Check a photo of your plant for free

pests on a plant
Photo: Jules Verne Times Two, CC BY-SA 4.0

Check these first

  1. Inspect the undersides of the leaves.
  2. Look for fine webbing near the stems.
  3. Check for sticky residue on the foliage.

Likely causes

  1. Aphids

    Most likely

    How to tell: Small green or black insects clustering on the undersides of leaves or new growth.

    What to do: Rinse the plant gently with a stream of water to dislodge the aphids. For larger infestations, use a mild insecticidal soap spray. Repeat the treatment every 5 to 7 days until they are gone.

  2. Spider mites

    Possible

    How to tell: Fine webbing between the leaves and tiny yellow stippling on the foliage.

    What to do: Increase the humidity around the plant by misting it daily. Wipe the leaves down with a damp cloth to remove the mites. Keep the plant well hydrated to discourage them from returning.

Pests on other plants

Find out what's wrong with your alligator weed

The list above covers the usual causes. Pocket Botanist looks at a photo of your actual plant and tells you the likely cause, how serious it is, and what to try first. Identification and a health check are free.

Download on the App StoreGet it on Google Play

When to worry

Worry if the leaves start to curl, yellow, or drop rapidly due to the infestation. It is normal to see an occasional stray bug that is not causing damage.

Stopping it coming back

Keep the plant well watered and maintain high humidity to make the environment less hospitable to common pests.

Alligator weed: pests? Check yours with a photo

Every plant is a little different. Take a photo of your alligator weed and Pocket Botanist tells you which cause is most likely, how serious it is, and what to try first. A few checks a day are free. Save the plant and you get care reminders timed for it.

Download on the App StoreGet it on Google Play

Get the app · Or check it from a photo now, free

Questions people ask

Can I use neem oil?
Yes, neem oil is effective, but use it sparingly. Ensure the plant is not in direct sun while the oil is on the leaves to prevent burning.
Why did I get pests on an aquatic plant?
Pests usually find their way onto plants through open windows or by hitching a ride on new plants. Keeping your plant healthy and hydrated is the best defense.

Guides to these causes

More problems with Alligator weed

Back to the Alligator weed guide

This article was generated with AI on from the plant’s care profile and is general information, not horticultural advice. Read about how we build these guides.