Thrips are tiny insects that can cause extensive damage to both garden and houseplants. They are so small that they can be tricky to identify, but they cause characteristic leaf discoloration that is easy to spot. But what can you do if you find thrips in your house, how can you get rid of them, and is there anything you can do to prevent thrips on your houseplants?
What are thrips?
Thrips are tiny insects that can infest a wide variety of indoor and outdoor plants. They are often black in color, but may also be yellow, brown, or gray. Adult thrips have narrow, feathery wings, but are not strong fliers. They are more likely to travel from plant to plant by hopping, crawling, or by floating on the wind.
Thrips have rasping-sucking mouthparts which they use to scrape away at plant tissue and suck out the juices of leaves, developing fruits, and flower tissues.
How common are thrips on houseplants?
Thrips can infest both houseplants and outdoor plants. They are more likely to affect plants in your garden, but they are also pretty common houseplant pests. For this reason, it’s always a good idea to inspect new houseplants thoroughly for thrips (and other pests) before taking them indoors.
Which types of houseplants are most likely to get thrips?
There are several common thrips species in the United States and, between them, they feed on a wide variety of plants. Thrips may attack fruit, vegetable, or flowering plants, including orchids and roses.
As thrips are more common outdoors, they are most likely to infest houseplants that have spent time in the garden. They are then transferred to your house (and other houseplants) when you bring the plant inside. Plants that you buy from garden centers may also have thrips living on them, so it’s important to check all plants for bugs before you bring them into your house.
How do thrips damage houseplants?
Thrips are so small that they can be difficult to spot, but the damage they cause to plants isn’t Thrips have rasping, sucking mouthparts that they use to suck the fluids out of plant tissue. Over time, the leaves of affected plants will start to look ‘dirty,’ with browned edges and white or silvery streaks. Damaged leaves may also curl upwards or have a distorted shape.
Thrips on roses will cause discoloration of the flowers, which may also become deformed or fail to open. In cases where thrips feed on the terminal buds of houseplants, this may result in abnormal branching patterns and deformed growth. Severe thrips infestations can result in stunted growth or even early plant death.
How can you tell if your houseplant has thrips?
Thrips are tiny insects (around 2 mm long), so they can be hard to see. You may miss the insects themselves, but signs of thrips damage is often what alerts people to their presence. If you notice that the leaves or flowers of your houseplants appear discolored or deformed, take a closer look at the plant to find the culprit.
When checking for thrips, you need to look out for tiny, dark-colored bugs in the buds of houseplants and on the undersides of the leaves. If thrips are present, you may also see black, varnish-like specks of poo on the leaves of infested plants.
How to get rid of thrips on houseplants
If you suspect that your houseplants have thrips, you should act immediately to prevent serious damage. There are several easy, natural remedies for treating houseplants for thrips including water, insecticidal soaps, neem oil, and sticky traps.
Spray your plants
One very easy way to remove thrips from your houseplants is to wash them away with water. Take any infested pants outside and rinse them down with a hose, taking care to focus on the undersides of the leaves. This will probably remove a large chunk of the thrips population, but may not get rid of every single bug.
Use insecticidal soap
Once you’ve rinsed off your houseplants, the next step is to kill off any lingering thrips. One way to do this is to use an insecticidal soap to spray your plant. You can either buy a pre-made spray or make your own by combining one teaspoon of a mild liquid soap with one liter of water in a spray bottle. Spritz your plant from top to bottom with the solution to finish off any remaining insects.
Use neem oil
Neem oil is an essential oil with well-established insecticidal properties, and is a good alternative to soap for killing thrips. Mix a few drops of the oil with water in a spray bottle and apply directly to the leaves of infested plants to kill the thrips.
Set up sticky traps
Sticky traps are a valuable monitoring tool in your war on thrips (and other houseplant pests). Setting up sticky traps near your houseplant will help you to identify infestations, reduce the number of thrips on your plants, and see how your control efforts are going.
Quarantine new plants
Thrips usually invade houses when plants are brought inside from the garden, or brought home from garden centers.
New plants should be kept well away from your other houseplants until you have thoroughly inspected them and are sure they are 100% thrip-free.
Thrips infest a wide variety of house and garden plants, and may attack fruits, vegetables, and ornamental, flowering plants. Plants that have been kept outside are at the highest risk of thrips invasions, and can contaminate other houseplants if they are brought indoors.
Always inspect new plants carefully for insects before you bring them into your house. If you think one of your houseplants has a thrips problem, take care of it immediately to stop the damage from becoming too extensive, and to stop them from spreading to your other plants.