Thrips are a common houseplant pest, and are very small bodied, straw-colored insects with tiny feathery wings. They’re so small they can be tough to spot with the naked eye, and instead can sometimes be more easily identified as an animated line moving around the leaf’s veins that moves when disturbed. Blotchy reddish brown discoloration can also be an indication that a thrips infestation is present. They can reproduce asexually, and with no natural predators found in human spaces, they can quickly multiply and cause significant damage. Of all the common houseplant pests, thrips are perhaps the most challenging to deal with.
When routinely checking in with your plant, be certain to pay special attention to the undersides of the leaves, as this is where many of the most common houseplant pests make their home. This is where the leaves are most tender and succulent, and it’s where suckers like thrips can be spotted in action.
To treat a plant for thrips, the first step is to hose the plant down under the sink or shower faucet, dislodging the bugs. Take care not to overwater the soil with the runoff. If its not possible to move the plant to a water source, use a spray bottle and microfiber cloth and spray and wipe each leaf. Follow this with an insecticide, such as neem oil. Neem oil is a natural pesticide and leaf shine that’s been used for hundreds of years on crops and houseplants alike. Best of all, it’s non-toxic to birds, animals, and many beneficial insects. Mix the neem oil with water and apply it to the plant with a spray bottle, letting it rest for 5-10 minutes, and then wiping the leaves clean afterwards.
For serious infestations that are undeterred by neem oil, an insecticidal soap is a stronger treatment option to consider. When the insects are present, apply thoroughly to all of the plant’s surfaces and repeat every 10 days until you no longer see any of the bugs. Please note insecticide should be applied in the evening, or when the plant is removed from the direct sun, as sunlight combined with the insecticide can burn a plant.
No matter the treatment separate the affected plant from the rest of your collection while it recovers, taking special care to ensure that none of the plant’s leaves are touching another plant’s. For future prevention, thoroughly inspect plants before bringing them into your home and try regularly wiping down the leaves with water to deter thrips from returning.
Thrips are tiny insects that can cause major damage to indoor plants. Once thrips get established, they multiply rapidly and can be difficult to control However, with persistence and using the right treatment methods, you can get rid of thrips and keep them from coming back This comprehensive guide will teach you everything you need to know about treating thrips on houseplants.
What Are Thrips?
Thrips are very small slender insects that are often black or brown in color, but can also be yellowish or greenish. They have narrow bodies long fringed wings, and move quickly over plant surfaces.
An adult thrips is only about 1 to 2 millimeters long, so they can be hard to see with the naked eye. Thrips larvae are even smaller.
Thrips feed by piercing plant cells and sucking out the contents. This results in silvery or bronze scarring, dead patches, and distorted growth on leaves and flowers. They prefer new growth and tender plant tissues.
Signs of a Thrips Infestation
Here are some of the most common signs that thrips may be present on your houseplants:
- Silver or bronze spots or scars on leaves and flowers
- Black dots of fecal matter on leaves
- Stunted or distorted new growth
- Flowers that fail to open or are malformed
- White or gray speckles on leaf undersides
- Damaged leaves that turn brown and die
Check carefully along the veins and undersides of leaves, as this is where thrips like to hide. Look for the tiny insects moving around as well as the signs of damage they cause.
Where Do Thrips Come From?
Thrips can hitchhike indoors on new plants, enter through open doors or windows, or come in when bringing outdoor plants back inside. Some common ways thrips invade houseplants include:
- New plants purchased from a nursery or store
- Houseplants that spent the summer outside
- Fresh cut flowers or vegetables brought inside
- Blowing in from outdoor plants through open windows and doors
Thrips spread very quickly between houseplants that are in close contact. So isolating any infested plants is important to stop them from invading your whole collection.
Thrips Life Cycle
Thrips go through multiple life stages during their lifecycle: eggs, larvae, pupae, and adults.
- Adult females lay eggs into plant tissue.
- Eggs hatch into larvae which feed on the plants.
- Larvae drop into the soil and go through a pupal stage.
- Adult thrips then emerge from the soil and fly back up onto the plants to feed and lay more eggs.
The entire lifecycle can be completed in just two weeks. Thrips also reproduce asexually, so a single female can give rise to many offspring very rapidly. This allows thrips populations to explode quickly.
How to Get Rid of Thrips on Houseplants
Getting rid of thrips takes patience and persistence. It often requires repeated treatments over the course of several weeks to break their lifecycle. Here are the steps to treat thrips organically and stop the infestation:
Isolate Infested Plants
Quarantine any plants showing signs of thrips away from your other houseplants immediately. This helps prevent them from spreading.
Wash Plants
Give infested plants a good rinse to wash away some of the adults and larvae. Use room temperature water and take care not to overwater the soil. Wipe leaves (especially the undersides) with a damp cloth to further dislodge thrips.
Apply Insecticidal Soap
Insecticidal soap is effective at killing thrips on contact. Spray all plant surfaces, including the undersides of leaves. Let the soap sit for 5-10 minutes before wiping leaves clean. Repeat every 3-5 days for a few weeks.
Use Neem Oil
Neem oil kills thrips and also acts as a repellent. Mix neem oil with water according to label directions and thoroughly spray plants. Repeat treatments every 7-10 days for several weeks.
Apply Systemic Insecticide
Systemic insecticides are taken up by the plant’s roots and make its tissues toxic to feeding insects. Apply as a soil drench and repeat as directed on the product label, usually every 2-4 weeks.
Set Out Sticky Traps
Yellow or blue sticky traps will catch adult thrips flying around. Place traps near infested plants and monitor to help reduce the population.
Be Patient and Persistent
It takes repetition and consistency to break the thrips life cycle. Don’t give up too soon! Keep treating and monitoring until all signs of thrips are gone. Expect the process to take 4-6 weeks.
How to Prevent Thrips on Houseplants
Prevention is the best way to avoid disastrous thrips infestations. Here are some tips:
- Quarantine and closely inspect any new plants before introducing them
- Isolate plants that were outdoors for the summer for a few weeks before moving inside
- Regularly check houseplants for pests
- Provide good air circulation between plants
- Keep plants away from open doors and windows
- Clean plants with water to wash away potential pests
- Apply neem oil preventatively every 2-3 weeks in problem areas
Catching thrips early when populations are small makes them much easier to control. So vigilance and routine monitoring are key.
Frequently Asked Questions About Thrips on Houseplants
How do you know if you have thrips?
Look for tiny black or brown insects moving quickly on leaves, especially along veins and leaf undersides. Signs of damage like distorted growth, silver scarring, dead patches, and black fecal dots also indicate thrips are present.
What kills thrips on houseplants?
Insecticidal soap, neem oil, and systemic insecticides are most effective at killing thrips. Sticky traps can also help reduce adult populations. Strong water pressure can dislodge some thrips.
Do thrips lay eggs in soil?
Thrips pupae develop in the soil. Adult females then lay eggs into plant tissue above ground. Thrips don’t actually reside in the soil for long. Removing all of the soil generally isn’t effective against thrips.
How do you get rid of thrips permanently?
Getting rid of thrips for good requires treating repeatedly using different methods like insecticidal soap, neem, and sticky traps over the course of several weeks. This breaks their lifecycle at different stages. Maintaining vigilance and taking preventive measures are also key to keeping thrips away long-term.
Can thrips kill plants?
Thrips rarely kill mature plants, but they can stunt growth and damage foliage and flowers. Young seedlings or small plants can decline and die from heavy thrips damage. Keeping thrips under control is important to prevent serious harm to houseplants.
The Bottom Line
Thrips can be challenging pests, but don’t let them get the best of your houseplants! Now that you know what to look for and how to treat thrips effectively, you can take action at the first signs of damage. Combining different organic control methods and persistence is the proven way to get rid of thrips and keep them from coming back.
