Thrips on Houseplants: A Comprehensive Guide to Identification and Treatment

Thrips are an incredibly frustrating and persistent pest that can wreak havoc on your houseplants. Dealing with these tiny insects requires a practical and effective approach to eliminate the infestation.

In this comprehensive guide, we will explore everything you need to know about thrips on houseplants, including their lifecycle, identification, and treatment methods.

Understanding Thrips

Thrips are small pests that often go unnoticed until you see the damage they cause. Most thrips measure only about 1mm in length and have a narrow body.

While adult thrips are commonly black, they can also appear in various colors. On the other hand, immature thrips, known as nymphs, have a lighter coloration.

Thrips damage plants by piercing holes in the leaves, flowers, and other plant parts and extracting the sap and juices. This results in silvery or brownish marks on the foliage.

Some species of thrips even leave dark deposits, which are essentially their excrement. It’s important to inspect the undersides of leaves as well, as thrips damage may be more prominent there.

The Lifecycle of Thrips

To effectively treat for thrips, it’s crucial to understand their lifecycle. Female thrips insert their eggs into the plant’s foliage, flowers, and stems. Once the eggs hatch, the nymphs start feeding on the plant.

In most cases, fully grown nymphs drop to the soil, where they undergo the pupal stage. After this stage, they transform into adults and fly back up to the plant, perpetuating the cycle of destruction.

Under optimal conditions, thrips can complete their lifecycle in as little as two weeks. The problem with managing thrips is that insecticide sprays only kill nymphs and adults, while the eggs remain protected inside the plant’s tissue. Therefore, a comprehensive treatment plan is essential to eradicate thrips completely.

Identifying Thrips Damage

Thrips damage can manifest in various ways, and it’s important to correctly identify the signs. Look out for the following indicators:

  1. Silvery or brownish marks on foliage: Thrips feeding on plant sap can cause discoloration, resulting in silvery or brownish marks on the leaves.
  2. Dark deposits or streaks: Some thrips species leave dark deposits on the plant, resembling thrips poop. Additionally, flowers and leaves may develop silvery streaks due to thrips damage.
  3. Distorted growth: Thrips feeding on the growing points of plants can cause gnarly and contorted growth.
  4. Inspect the undersides of leaves: Thrips damage may be more visible on the undersides of leaves, so be sure to check there as well.

Dealing with Thrips on Houseplants

When it comes to treating thrips on houseplants, a multi-step approach is necessary for effective control. Follow these steps to manage and eliminate thrips effectively:

1. Remove Heavily Infested Plant Parts

Start by cutting off or trimming away any heavily infested leaves or flowers. Dispose of the infested plant parts in a sealed bag to prevent the spread of thrips.

2. Wash Down Your Plant

Take your plant to a sink or shower, or even outdoors if the weather permits, and thoroughly rinse off the entire plant. Pay special attention to the undersides of leaves, as thrips often hide there. This initial wash helps to knock down the thrips population on your plant.

3. Use Insecticidal Soap

After drying your plant, apply a good insecticidal soap to all surfaces, including the undersides of leaves. Insecticidal soap is effective in killing both nymphs and adult thrips upon contact.

Bonide Insecticidal Soap is a reliable product for this purpose, but be sure to test it on a small portion of the plant first, especially if you have sensitive species like succulents, ferns, or begonias.

4. Apply a Systemic Insecticide

Since insecticide sprays cannot eliminate thrips eggs buried within the plant’s tissue, a systemic insecticide is crucial for complete control.

Sprinkle the recommended amount of a systemic insecticide, such as Bonide Systemic Houseplant Insect Control, into the soil and water it in. The plant will absorb the insecticide, poisoning thrips when they feed on the plant.

5. Utilize Sticky Traps

To capture adult thrips and prevent them from laying eggs, use sticky traps. Yellow sticky traps, commonly used for fungus gnats, are also effective in catching thrips.

Place the traps in the pot of your infested plants and monitor them regularly. Blue sticky traps are particularly attractive to thrips and can be used in combination with yellow traps for increased effectiveness.

6. Repeat Washing and Spraying

Thrips have different lifecycle stages, so it’s important to repeat the washing and spraying steps weekly. Regular treatment ensures that you kill as many thrips as possible and prevent new damage.

Be diligent in maintaining this routine for several weeks to effectively break the thrips lifecycle.

Preventing Thrips Infestations

Prevention is always better than cure when it comes to pests. Here are some preventive measures to minimize the risk of thrips infestations on your houseplants:

  • Give your plants regular showers to knock off any potential thrips and keep them free from dust, promoting overall plant health.
  • Inspect any new plants you purchase carefully to avoid bringing home infested plants. Quarantine new plants for 2-3 weeks to monitor for signs of thrips before introducing them to your existing collection.
  • Increase humidity levels with the help of a humidifier. Thrips, like spider mites, prefer drier air, so maintaining higher humidity can deter them.
  • Regularly inspect your plants for any signs of pests. Catching a thrips infestation early makes it easier to treat and prevent further damage.

Recommended Products

Here are some products that can assist in the treatment and prevention of thrips on houseplants:

  • Bonide Insecticidal Soap: A reliable insecticidal soap for treating thrips and other pests on your plants.
  • Yellow Sticky Traps: Use these traps to capture adult thrips and prevent them from laying eggs.
  • Blue Sticky Traps: Particularly attractive to thrips, these traps can be used in combination with yellow traps for increased effectiveness.
  • Bonide Systemic Houseplant Insect Control: A systemic insecticide that can be applied to the soil to eliminate thrips and break their lifecycle.


Thrips on houseplants can be a frustrating challenge, but with the right approach, you can effectively manage and eliminate these pests. By understanding their lifecycle, identifying thrips damage, and following a comprehensive treatment plan, you can successfully rid your plants of these troublesome insects.

Remember to be proactive in preventing thrips infestations and regularly inspecting your plants to catch any issues early on. With proper care and attention, you can enjoy healthy, thriving houseplants free from thrips.

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