Thrips on Monstera: 8 Ways to Stop Them Quickly

Monstera thrips cause so much damage they can kill your indoor or outdoor Monstera in a few months. Unfortunately, it’s a common problem that spreads through co-habiting plants like wildfire, so it’s important to regularly check plants for infestations and deal with them pronto. This article uncovers thrips on Monstera and eight ways to stop them quickly.

What’s a Thrip?

A thrip is a houseplant terror, a tiny vampire that sucks the life force from your beautiful (and expensive) Monstera.

Also known as thunderflies, thrips sit in the Thysanoptera order. So far, experts have discovered 7,700 species! A distinctive needle-wide cigar-shaped body with an average maximum length of around a millimeter (0.039 inches) keeps them well hidden in your leafy green plants.

Thrip color varies from white to dark brown, but in general, they all have strap-like wings with a delicate fringe of hair. Juvenile thrips that haven’t yet developed wings appear creamy-yellow. Their miniature eggs are so small it’s all but impossible to spot them with the naked eye.

Despite their tiny size, they wreak havoc in a garden, greenhouse, or home as they suck out precious leaves, buds, and flower sap before breeding at a rate of knots. Mature female thrips dig a small slit in foliage and lay their eggs directly in the leaf. They hatch out a few days later, spend a few weeks growing, and then lay eggs. It’s a hard-to-break cycle of Monstera destruction.

Signs and Symptoms of Thrips

Tiny thrips’ foliage damage is often the first sign of an infestation.

Symptoms include leaf curling, browning, yellowing, and drooping. You might also spot tiny black feces on leaf undersides. For surety, shake foliage above a piece of white paper and take a photo. Use the enlarge feature, and you might spot one.  

That said, sometimes no obvious symptoms arise, and all you can see is a Monstera that isn’t thriving. If you have a good watering regime, and your Monstera receives appropriate light and fertilizer, an all but invisible thrip infestation might be to blame.

Here are eight ways to get rid of thrips on a monstera (and other houseplants) quickly and effectively. Don’t hang around! The longer you leave it, the more difficult it is to evict them.

But first, quarantine an infected indoor monstera to prevent spread. It’s probably too late, but you can hope!

1. Pesticides

Not everyone likes pesticides, and it’s true their impact on the environment is destructive, but it’s a quick way to destroy a thrip infestation. Many plant owners reach for commercially bought organic sprays, such as natural pyrethrum, but any plant pesticide that’s suitable for Monstera will kill thrips.

Treat outdoor plants in the evening to keep bees a little safer. Indoors, it’s up to you, but open a window because plant pesticides can cause breathing difficulties. Pop on a pair of gloves, then spray along each stem, beneath each leaf, then cover each leaf top. Spray the soil and let it dry.

Unfortunately, because thrips spread, you’ll have to treat other houseplants too.

2. Sticky Traps

Sticky traps catch thrips as they move around, but they’re indiscriminate and stick to any passing insect, including butterflies. They also stick to hair, so apply caution when bending over to check your monstera for progress. There’s nothing worse than a fly-encrusted sticky trap stuck to your curls!

Research indicates thrips prefer blue and yellow over red, so keep an eye out for those shades online or in your local garden center. Inexpensive sticky traps come as dangling tape, small post-it style blocks, and small strips that attach directly to a pot. Alternatively, smear honey on a blue or yellow piece of paper.

3. Lint Roller

Applying a lint roller to severe thrip infestations is satisfying and gets immediate results. It won’t remove them all, and you’ll need to apply another method to clear out the eggs, but it feels good! Hold a Monstera leaf flat on your palm and apply the sticky roller. Be sure to roll both sides.

4. Natural Predators

Some animals love thrips, it’s not us, but ladybugs and specific mites think a thrip is delicious.

There’s no need to chase ladybugs around the yard. It’s possible to buy them online and release them into Monstera soil. If you do so indoors, be aware they’ll fly around onto other plants, too.

Another option is the Amblyseius cucumeris mite. Unlike ladybugs that eat adult thrips, these mites prefer thrip eggs and larvae, so they help break the lifecycle. Buy anti-thrip mites online and release them into Monstera soil. Within a week or two, you should start to notice the difference.

5. Use Neem Oil

Neem oil is extracted from neem tree seeds. It’s a natural pesticide used in a wide variety of products, but it’s especially good at killing plant pests because it doesn’t damage foliage or flowers.

Spray or rub neem oil onto Monstera leaves, into the crevices, and down the main stem. Use a Q-tip to really get into thrip-friendly gaps. Follow the bottle’s dilution directions and let the mixture dry naturally.

6. Insecticidal Soap

Make up a mixture of insecticidal soap with water and spray it over the foliage. Let it dry out, and you should quickly see an improvement. Insecticidal soap is suitable for indoor and outdoor monstera, but excessive use burns foliage, so follow the packet directions carefully.

7. Remove Damaged Leaves

Last resort time!

A massive infestation that’s caused visible damage is often best controlled by removing infested leaves. It’s heartbreaking to chop a Monstera’s large notched leaves off, but it’ll stop those eggs from hatching, and the affected leaf won’t recover anyway. Once an under-attack leaf is removed, your Monstera can direct that energy into new healthy growth.

However, even if you chop an infested leaf, you’ll still need to treat its remaining foliage ASAP.

8. Diatomaceous Earth

Sharp diatomaceous earth particles cut fallen eggs, larvae, and adults, and it draws out their body moisture. It’s handy indoors, but outside, it’ll damage beneficial bugs, too.

Why Are Thrips So Hard to Get Rid Of?

Thrip lifecycle is to blame for their monstera-killing persistence. Killing the adults is just one step of the process. Thrip eggs hatch quickly, and the cycle repeats. Thrips are poor fliers, but they can travel and infest most types of plants. Once your Monstera’s clear, you could find it’s quickly re-infected from an untreated neighbor.

However, it is possible to kill thrips. Be as persistent as them, repeat treatments, and eventually, you’ll break the cycle.

How to Prevent Thrips

With the best will in the world, most gardeners receive a direct hit from thrips. With over 7,000 species, it’s really just a matter of time. One of the best ways to deal with thrips is prevention because they will come for you eventually!

Here are some thrip prevention top tips.

• Quarantine all new plants: Before introducing a new plant, check it thoroughly for thrips. It’s best to leave the newbie in a room without plants for a few days to monitor the situation first. This can save a lot of heartache.
• Apply regular neem oil: Non-toxic neem oil sprayed once a month is a good way to deter thrips and kill an unnoticed infestation early on.
• Clean foliage: Wipe down Monstera leaves regularly. Not only does this remove dust build-up, but it’s a chance to nip emerging problems quite literally in the bud.
• Own healthy plants: Healthy Monstera will survive thrip attack, but weak plants may succumb. Ensure your monstera receives adequate light, water, and fertilizer, and re-pot it when necessary. You can learn about top-notch monstera care here.
• Encourage predators: Thrips provide nutrition for ladybugs, parasitic wasps, and lacewings.
• Grow repellent neighbors: Monstera may benefit from companion plants such as catnip, basil, mint, oregano, chives, and garlic. Try an indoor mint plant – you’ll love its fresh, clean scent as well as its thrip-repelling properties!

The photo featured at the top of this post is © Dan Gabriel Atanasie/Shutterstock.com