How to Identify, Treat & Prevent Thrips on Your Monstera
Thrips are one of the few pests that Monstera are prone to. They can be one of the more annoying pests to deal with because they have a longer life cycle than other houseplant pests. They can also fly away from pest treatments, making treatment extremely difficult. Early detection & aggressive treatment are key to ensuring you get rid of thrips for good.
What are Thrips?
Thrips are common garden pests. They are small, flying insects that leech nutrients & water from your plants to survive. Don’t worry about seeing them buzzing about your plants, though. Thrips have fringed wings, which make them weak flyers. You’ll most likely see the flightless nymphs before noticing adults. Thrips lay their eggs inside your Monstera’s leaves & other soft tissues. After hatching, nymphs are right in view & usually huddled together to feast on your plant.
Thrip Life Cycle
Thrips have one of the longest life cycles of all the common pests & can live up to 45 days as an adult. That’s 45 days of laying eggs in your leaves. Now you can see why thrips infestations can get out of hand so fast & need a lot of persistence to beat.
From an egg, it takes about 21 days to evolve into an adult. As an egg, they’re detectable by the puncture holes left by the adults used to lay the egg inside the soft tissue. You will not actually be able to see the eggs since they are microscopic. After 3-5 days, the egg hatches into a nymph. They live as nymphs for 4-6 days before pupating for 1-3 days. After pupation, they become adults & can live anywhere from 30-45 days.
Tip: The lifecycle of a thrip is 60+ days – I stay persistent with treatments for up to 3 months after the last thrip sighting among my plants to ensure they do not come back.
Signs of Thrips on Your Monstera
Unless it’s a full-blown infestation, it may be hard to see the bugs on your plants. They like to nestle on the underside of leaves & in crevices, but it is not uncommon to see them on the tops of leaves. Most of the time, they will huddle together, but sometimes you will see them moving across the top of the leaf alone.
If you have an established plant that suddenly declines, you may have an infestation developing. Your leaves may start to droop or yellow. And when you look closer, you’ll see tiny black/ brown spots where it’s yellowing.
This can be a sign of other pests as well, so make sure to check for the small white nymphs or black/green adults on your leaves.
Tip: If you’ve inspected & you’re still not sure if you have thrips, put a piece of white or black paper under the leaves, then shake or tap the leaves over the paper. The bugs should fall down onto the paper.
What Do Thrips Look Like On Leaves?
You can see both adult thrips & nymphs on the leaves, but most likely, an adult thrip is going to hide before you can see it.
Nymphs are off-white & small, almost resembling dirt or dust. If you get up close, you can see the nymphs scurry along the leaves.
Adults can be brown, black, white, green, or yellowish-green. They have pointed backs & they’re generally upturned if they are not in flight.
What does Thrips damage look like on leaves?
During a thrip infestation, your plant’s leaves may start drooping or curling.
You may notice more serious & irreversible damage, such as yellowing spots on your leaves.
You’ll also notice small puncture wounds/scars where thrips feed or lay eggs on your Monstera’s leaves.
How Did My Monstera Get Thrips?
Thrips are common, and they can come from anywhere.
They can come in with fresh produce, cut flowers, or new houseplants you bring home from the store or your own garden. They could even come in on your clothes after a trip to an area they’ve nested.
How Do You Treat Thrips on Your Monstera?
There are a few different ways you can get rid of thrips for good, both natural & more aggressive.
It’s important that you stay consistent with your chosen treatment form. Thrips reproduce both sexually & asexually. That means even if you leave one little bug, you’re going to have another infestation on your hands in no time.
1. Chemical Pesticides
Chemical Pesticides (like Sevin or Spectracide) is a surefire way to get rid of pests & prevent them from coming back. The chemicals in pesticides can be harmful to humans as well, so make sure to use them in well-ventilated areas & follow the instructions.
When treating with chemical pesticides, you’ll want to ensure you’re treating during thrip downtimes. Otherwise, they will fly away and harbor away until the coast is clear. Thrips are diurnal creatures, so they’re active throughout the day. Their peak hours are roughly 8-10 am and 2-4 pm, so the best time to treat is in the evening.
2. Neem Oil
Neem oil is a natural method of pest control. Neem oil can kill pests on contact & is great for preventing thrips from returning to your plants. This method will also harm other insects that could come in contact with your plants. If you’re using beneficial insects or have pollinators that come near your plant, think twice about using this method.
The best time to treat with Neem Oil is also in the evening. Neem oil can make the leaves sensitive to light & cause burn or scorch marks on your leaves.
- Use a Neem Oil solution in a spray bottle to saturate the leaves (Buy premixed or concentrate to mix your own according to the instructions)
- With a microfiber towel, wipe your leaves in entirety. Make sure to wipe all the veins and areas you may see any damage or bugs.
- Using a spray bottle with only water, spray your leaves again.
- Using the microfiber towel, wipe down your leaves again, ensuring to wipe down any part of the leaf that is exposed to sun or light.
Repeat this process 2-3 times per week for up to 120 days to ensure that your thrips infestation is under control.
For added effectiveness, add a drop of Dawn dish soap & leave on overnight. If you leave your solution on overnight, be sure to rinse it off before morning light, so your leaves aren’t permanently burned.
FURTHER READING: A Complete Guide to Neem Oil for Indoor Plants
3. Hydrogen Peroxide Solution
A hydrogen peroxide solution can kill thrips pupae, but may not be as effective on eggs & ineffective on adults. Because larvae can fall off the leaves into the soil to pupate, you want to make sure you also treat the soil.
I recommend mixing a 10% Hydrogen Peroxide to 90% water solution, but if your infestation is severe enough, you may want to increase that to 15-20%. Use this solution as a part of your regular watering & make sure to saturate the soil with the solution. You can also put this solution into a spray bottle and treat your leaves.
4. Beneficial Insects
Recommended Brand: Nature’s Good Guys
Beneficial insects like ladybugs, lacewings & predatory mites are all great ways to keep pests under control. Predatory mites (Amblyseius cucumeris) are the most preferred because they’re small & they hunt down their prey – thrips & spider mites.
When using beneficial insects, they may stray throughout your house & end up in inconvenient areas. This can take some time to get rid of an infestation, but it is very effective. These helpful critters hunt for thrips & other pests in your plants to feast on them. After you receive your insects, they’ll come with specific instructions for releasing & caring for them. Typically, all you’ll need to do is release them on or around your plants that are free from pesticides.
Tip: Predatory Mites are effective in planted terrariums, especially bioactive reptile/amphibian enclosures.
Should You Throw A Plant With Thrips Away?
If you don’t have space to quarantine your plant or the infestation on the plant is bad enough, throwing away your plant is an option. Thrips are a pain to get rid of & spread fast because they can fly.
If your plant is sentimental to you, this isn’t an option you want to consider until you’ve exhausted all others. With persistence & confidence, no infestation is too large. Monstera plants are resilient and can recover quickly during the growing season, even if you need to remove all the leaves.
Tip: Wrap in a bag or many bags to prevent the infestation from spreading to your other plants.
Should I Remove Leaves With Thrip Damage?
Thrips lay their eggs inside the leaves, so removing infested leaves can help you get an infestation under control. Damaged leaves drain energy from the plant & can stunt growth. But, if the leaf isn’t damaged severely, you may consider keeping it. Since traveling is easy enough for thrips, they’ll likely affect many leaves of a plant.
In my most recent experience with thrips on my Monstera, if I removed all the leaves with damage, I wouldn’t have any leaves left on my plant. In this case, I removed severely damaged leaves but left ones that didn’t have bad damage. The downside? It affects the aesthetics of my plant because the damaged leaves will never recover.
Should I Repot My Monstera After A Thrips Infestation?
If you’ve had a large infestation, it’ll be a good idea to repot your plant & dispose of the soil in the pot. This isn’t an option for everyone because large Monstera plants can use a lot of soil & soil can get expensive. Especially if you’re replacing your soil every time you see a pest.
With persistence, you can bring any infestation under control.
How Do Thrips Spread?
Thrips can fly, though not very well. It’s well enough to move from plant to plant. In comparison to other houseplant pests, thrips spread quickly. Thrips generally hitchhike from place to place, landing on plants, flowers, or even clothes. Once they’ve hitchhiked most of the way to their target, they use their frayed wings to take them the rest of the way.
How Do I Prevent Thrips?
Thrips are common in gardens, especially in temperate areas. If you live in one of these areas, it’s unlikely you’ll ever completely prevent your plants from getting thrips. Basic precautions like routine pest inspections can make all the difference in pest prevention. You can also use systemic insecticides, repelling plants, & quarantines in your pest prevention.
1. Systemic Insecticides
Using systemic insecticides in your soil is the most effective way to keep pests at bay. Systemic insecticides take time to work because they work from the outside in.
There are a few application methods for systemic, but they all have the same basic concept. The plant absorbs the insecticides from the soil through the roots & spread through the entire plant. It is effective because once a pest feeds on your plant, it will also be ingesting the insecticide.
2. Quarantine & Repot New Plants
It is always a good idea to quarantine all new plants you’re introducing into your home garden. This alone may not keep you safe from an infestation, but this will reduce the chances of you bringing in hitchhikers with your new plants.
Repotting plants and removing as much soil as possible will make sure you’re not carrying any thrip adults or pupae in the soil. Besides the leaves, adults hide in leaf litter, bark & other organic material near the top of your soil. Also, larvae can sometimes fall from the leaves to pupate in the soil. You don’t want to risk keeping the soil if you think they may be there.
3. Thrip Repelling Plants
Herbs like oregano, basil & garlic tend to repel thrips & some other pests. Plant these around the base of your plant or in planters nearby for the best result.
Please note: this will not be a 100% effective way of keeping thrips away from your plant. But with these plants around, the thrips will search for somewhere more desirable to feast.
FAQs About Thrips On Monstera & Other Plants
Do thrips live in the soil?
It is not common to see thrips living in the soil, but not impossible. Nymphs may fall to the soil to pupate & adults can make a home in the soil through the winter. Other than that, you’ll only find thrips in the soil if they’re hiding from you.
How long can thrips live without plants?
Without plants, thrips could only survive a couple of days, but they will always try to find their way to another plant (and are usually successful).
Do thrips bite humans?
Thrips can & do bite humans. It is very similar to a mosquito or ant bite. They’re more likely to bite humans in the wild than in your home amongst your plants, but it’s not impossible.
Do thrips like wet soil?
No, thrips do not like wet soil. Thrips cannot survive well in wet conditions.
Can you wash off thrips?
Thrips fall off of your leaves easily when sprayed or wiped down. Even shaking the leaves can remove the thrips from your plant. Washing off thrips will not rescue your plant during an infestation.
What are the most natural ways to get rid of thrips?
Beneficial insects are the most natural way, with Neem Oil taking a close second. The reason Neem Oil isn’t number one is that it does harm native insects & pollinators too. I do not recommend using Neem Oil if your plant is going outside.