How to Defeat Thrips on Houseplants – The Ultimate Guide to Pest Control That Really Works

Welcome to the world of thrips, one of the most stubborn indoor pests. But here's the good news: you don't have to cut, set fire to, and/or yell at your plants. There's actually a solution that works long-term, and it's called beneficial insects.

No, it's not science fiction. Beneficial insects are small, helpful insects that eat your thrips while you sleep.

We at Ormbunker have been battling thrips for a long time, both in our greenhouse and at customers' homes. We've tried everything from chemical pesticides to home remedies that don't work. What actually solved the problem? Beneficial insects! Let us tell you how.

Treat or prevent, a crucial difference

An absolutely crucial piece of knowledge when purchasing livestock is to first know whether you are treating an existing outbreak or aiming to prevent future outbreaks.

Many of our beneficial animals come in small bags that are hung on the plants. They usually last about 4-6 weeks. In all the examples below, we recommend that in the event of an outbreak , the bags be replaced with new ones every 4 weeks. In the event of an outbreak, it is sufficient to replace the bags every 4-7 weeks instead.

When Thrips Strike: How to Treat the Outbreak Smartly

First things first: panicking won’t help. Thrips are annoying, but they’re not immortal. The first thing you need to do is identify what type of thrips you’re dealing with. Yes, there are actually different species, and they require different treatments. But no matter what type you’re dealing with, there are some basic rules for how to deal with the outbreak.

Isolate first, treat later: When you discover thrips on a plant, immediately move it away from your other plants. Thrips spread faster than rumors, and you don't want your entire plant collection to be affected. Quarantine the affected plant while you plan your attack.

Map the damage Look closely at the plant. Thrips cause characteristic damage, silvery or bronze-colored spots on the leaves, small black dots (their feces) and sometimes you will notice the small, yellow or white larvae moving on the underside of the leaves. If the plant is already losing leaves massively or has large yellow areas, the outbreak is quite advanced.

Act fast with livestock Now comes the important part: buy livestock as soon as possible. Many people think they should "clean first" with chemicals and then release the livestock, but that's the opposite. Livestock are your best weapons from day one, and they work best when they get an early start.

What we have learned over the years is that beneficial animals actually work better indoors than outdoors, because the environment is more controlled. Your houseplants become like little ecosystems where beneficial animals can thrive and do their job.

Frankliniella occidentalis: The Most Common Offender

Ah, western thrips. If you only have one type of thrips at home, it's probably this one. Frankliniella occidentalis are like the generalists of the thrips world, they eat almost anything and thrive in most environments. We see them constantly on everything from banana plants to monsteras, and they are masters at hiding on the undersides of leaves.

How to Recognize Them: Franklinella thrips are small (1-2 mm) and range in color from light yellow to dark brown. They move quickly when disturbed, and their larvae are creamy white to light yellow. The damage they cause appears as silvery spots that may later turn brown, and the plants often take on a dull, almost dusty appearance.

Best beneficial insects: For franklinella we mainly recommend the Montdorensis-System . These predatory mites have become our first choice after years of testing, they are incredibly effective against both adult thrips and larvae, reach everywhere on the plant and establish themselves quickly. Montdorensis mites are also more persistent than many other beneficial insects and continue to hunt thrips even in tougher conditions.

Orius-System works great as a supplement, especially for larger outbreaks. The Orius beetles eat both adult thrips and larvae with an impressive appetite, an adult Orius beetle can eat up to 20 thrips per day.

The Amblyseius Breeding System is perfect if you have a larger collection of plants. This system establishes a sustainable population of predatory mites that continually keep the thrips population down. Think of it as insurance against future outbreaks.

Franklinella are stubborn, but they are not impossible to get rid of. The key is to be consistent and give the beneficials time to establish themselves. Expect 2-3 weeks before you see significant improvement.

Echinothrips americanus: The Stubborn American

If Franklinella are the generalists, then Echinothrips americanus are the specialists. These thrips have a preference for green plants and other plants with thicker leaves. They are also significantly more persistent and can cause more serious damage in a shorter period of time.

Identification: Echinothrips are darker than Franklinella, often almost black with lighter legs. They are also slightly larger and their larvae have characteristic dark spots. The damage they cause is often more extensive, large silvery areas that quickly turn brown and dead leaf tissue.

Treatment strategies: For Echinothrips you really need to be patient. Orius is our first choice here. You can also supplement with Montdorensis.

A tip we learned: Echinothrips love dry air, so increase the humidity around your plants. This makes them more receptive to the beneficial insects and helps the plants recover faster.

Thrips parvispinus: The Tropical Infection

Thrips parvispinus, or yellow thrips as it is sometimes called, has become more common in Swedish homes in recent years. It often arrives with new plants from tropical cultivations and thrives wonderfully in our heated homes.

Characteristics: These thrips are light yellow to orange and relatively large. They prefer young leaves and plant tops, which makes the damage often extra visible. You often see them as a yellowish mass on new shoots, and the plants often develop deformed leaves.

Effective Treatment:Montdorensis is our first choice for Thrips parvispinus. Montorensis seems to have a special ability to handle this species, perhaps because both come from tropical environments originally.

Hypoaspis also works well, especially in combination with Montdorensis. For severe outbreaks, you can add Orius beetles but be prepared that it will take time.

Thrips parvispinus seem to be more resistant than other species, so expect 4-6 weeks for full control.

Thrips setosus: The Hidden Enemy

Thrips setosus are masters at hiding. They thrive in leaf crevices, under buds, and other hard-to-reach places, making them extra difficult to detect and treat.

Identification and Behavior: Thrips setosus are small and dark, often almost black. They move less than other thrips species and prefer to sit still in their hiding places. The damage often comes as a surprise, suddenly the plant has large damaged areas without you seeing many thrips.

Specialized Treatment: For Thrips setosus you need beneficial insects that can get everywhere. Hypoaspis is invaluable as these mites crawl into small crevices and actively search for thrips.

Amblyseius cucumeris 'thrip predatory mites' also work well because predatory mites are generally better at finding hidden thrips than orius beetles are.

Feel free to combine with Montdorensis-System to cover all bases. The important thing with Thrips setosus is to be patient, the results come slower but are more lasting once the beneficial insects have found all the hiding places.

Chaetanaphothrips orchidii: The Orchid Specialist

As the name suggests, these thrips love orchids, but they also thrive on other delicate plants like violets and begonias. They are particularly problematic because they often damage flower buds and new shoots.

Special Challenges: Chaetanaphothrips orchidii often lives inside flower corollas and on other delicate parts of the plant. This makes treatment complicated because you cannot use aggressive methods without damaging the plant itself.

Gentle but Effective Treatment: Montdorensis is perfect here because these mites are small enough to work on sensitive plant parts without causing damage. They are also gentle in their behavior, which suits sensitive plants.

Avoid Orius-System on orchids, the orius beetles can be too aggressive and cause damage to the delicate flowers.

Scirtothrips dorsalis: The Asian Opponent

Scirtothrips dorsalis, also known as chili thrips, have become more common on houseplants in recent years. They are particularly problematic on plants with soft leaves such as basil, chili plants and other herbs.

Characteristics: These thrips are light, almost translucent when young, turning yellowish as they mature. They cause characteristic silvery streaks along the leaf veins, and the damage can quickly cause entire leaves to turn brown and die.

Intensive Treatment Strategy: Scirtothrips dorsalis requires a combined approach. Orius together with Montdorensis gives the best results. The Orius beetles handle the adult thrips while Montdorensis takes care of the larvae.

Hypoaspis is also valuable because many larvae pupate in the soil around the plant base.

For this species, we recommend that you also increase the humidity significantly. Scirtothrips dorsalis thrive in dry air, so humidity makes them more vulnerable to beneficial insects.

Practical Tips for Success with Livestock

How long do beneficial insects live? This is one of the most common questions we get. Orius beetles live 3-5 weeks as adults, predatory mites such as Montdorensis, Ambylesius or Awirskii 2-4 weeks. But the important thing is not how long they live individually, but how long the system works. With the right conditions and regular purchases of beneficial insects (about every 4-6 weeks), the plants can be completely free of thrips for years to come.

Best beneficial animals against thrips, our ranking:

Orius – best all-round choice for most thrips species

Montdorensis – fast and effective against most thrips

Hypoaspis – invaluable for soil-borne larvae

Swirskii – perfect for long-term control

Amblyseius – good for large collections and immediate effect.

How to Use the Bags Correctly: Our beneficial insects often come in special bags that are hung on the plant. Hang the bags in shady places on the plant where it doesn't get too hot. The bags have a small hole where the beneficial insects come out gradually, not all at once.

Environmental Factors That Influence Success:

Temperature: 20-25°C is optimal for most livestock

Humidity: 60-70% helps both beneficial animals and plants

Light: Avoid direct bright light on the bags of livestock

Air circulation: Light air movement is good, but avoid drafts

Common Mistakes to Avoid:

Do not use insecticides at the same time as releasing livestock

Don't give up too soon: it takes time to see results

Don't forget to follow up with new bags according to schedule.

Don't just treat the affected plant: also combat thrips on the plants in the entire room

Conclusion

After years of fighting thrips in various ways, we have learned that beneficial insects are not only the most effective solution, they are also the most sustainable. Instead of constantly spraying chemicals that thrips eventually become resistant to, you build up a natural defense that adapts and renews itself.

Yes, it takes patience. Yes, it costs more up front than a spray from the hardware store. But once you see how orius beetles methodically clean up your plants of thrips, and when you notice that outbreaks become fewer and less severe, you'll understand why we always recommend beneficial insects as the first choice.

Remember, thrips are not a sign that you are bad at plants. They are just a part of the reality of plant life, just like weeds in the garden. But with the right tools, and beneficial insects are definitely the right tools, you can keep them under control and enjoy healthy, green plants all year round.

Do you have questions about which beneficial insects are right for your plants? Contact us, we have probably fought the same thrips that are plaguing you right now!