Thrips are a common pest on both outdoor and indoor plants. They cause damage by feeding on plant sap, destroying plant tissues with their chewing mouthparts. These insects thrive in warm conditions, becoming a bigger problem outdoors during summer months.
Because they are tiny and multiply rapidly, thrips can go undetected until a serious infestation is already underway. Many of the symptoms of thrips are similar to other pests and even some diseases, so it’s crucial to know the source of the problem before treating affected plants.
There are more than 6,000 species of thrips, many of which are harmful to plants. Many species prefer feeding on certain plants, so are often named for the host plant, such as onion thrips, pea thrips, gladiolus thrips, or rose thrips.
What do thrips look like? Thrips are soft-bodied, cigar-shaped insects, reaching just 1/25-inch long. They are brown, black, or yellow; some with colored markings. They have narrow, fringed wings, but are poor fliers. Nymphs look similar to adults, but are smaller and wingless.
Thrips are tiny, slender insects that can cause serious damage to plants. These tiny pests are difficult to spot with the naked eye and can rapidly spread to infest entire gardens and houseplants. Learning how to identify thrips using pictures is key for controlling these harmful insects.
In this article we’ll cover
- What are thrips?
- What do thrips look like on plants?
- Thrips damage on leaves, flowers, and fruit
- How to treat a thrips infestation
What Are Thrips?
Thrips are tiny winged insects measuring around 1/50 to 1/8 inch in length. There are over 6000 species of thrips that come in different colors like yellow, dark brown, or black. They have narrow bodies and fringed wings that reflect light.
These tiny bugs are sap-sucking insects that use their piercing mouthparts to feed on plant cells Thrips rasp plant tissues and suck up the sap, causing stippling, discoloration, and deformities in leaves, buds, and fruits
Thrips also spread viral plant diseases as they move between plants. Some of the most destructive thrips-transmitted diseases include tomato spotted wilt impatiens necrotic spot, and cucumber necrosis virus.
What Do Thrips Look Like on Plants?
Identifying thrips takes a careful eye since these insects are incredibly small. Here are some tips for spotting thrips:
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Look for tiny, slender dark or straw-colored bodies on leaves and petals. Thrips may fly away or leap off the plant if disturbed.
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Use a magnifying glass to inspect leaves closely. Pinpoint tiny moving insects against the plant surface.
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Shake foliage over white paper to dislodge thrips. Look for rice-shaped black or brown specks on the paper that jump and crawl around.
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Check for black tar-like spots of thrips excrement on leaves and petals.
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Notice if flower petals or leaves have a sandpaper-like texture. This is due to thrips rasping the surface.
Thrips Damage on Leaves, Flowers, and Fruits
Thrips feed by puncturing plant cells and sucking up the contents. This causes blotchy spots, dead patches, discoloration, and deformities on the plants they infest. Here are some common types of thrips damage:
Leaf Damage
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Silvery or whitish streaks and patches on leaves. This is due to the insects sucking out the inner content of leaf cells, leaving just the outer cell walls behind.
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Brown, black, or reddish scarring and stippling on leaves.
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Distorted, stunted growth in new leaves and shoots.
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Dry, curling leaf edges in seriously damaged plants.
Flower Damage
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Discolored, streaked petals on flowers like roses, zinnias, and dahlias.
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Flowers may be misshapen, stunted, or fail to open fully.
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Brown scars and dead spots on petals. Pollen will also be eaten by thrips.
Fruit Damage
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Pale blotches, dimples, and scars on fruits. Common on apples, peaches, nectarines, and citrus fruits.
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Russeting or bronzing of fruit skin, especially on apples and pears.
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Premature fruit drop.
How to Treat a Thrips Infestation
If you suspect thrips, take action quickly to avoid damage. Here are some effective organic and chemical treatment options:
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Knock thrips off plants by spraying leaves vigorously with water. Repeat daily to disrupt their life cycle.
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Apply insecticidal soap or neem oil to suffocate adult thrips and larvae. Target the undersides of leaves and stems.
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Use spinosad or azadirachtin sprays derived from natural bacteria and plants. These biological insecticides kill thrips larvae.
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Dust plants with diatomaceous earth. The sharp particles cut thrips and cause dehydration. Focus on leaf undersides.
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Set out sticky traps to monitor and reduce thrips populations. Blue or yellow traps attract adult thrips.
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Apply horticultural oil or pyrethrin sprays to kill thrips eggs and larvae hiding in plant crevices.
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Systemic insecticides like imidacloprid are taken up by plants’ vascular systems to kill thrips feeding on plant juices. Use as a last resort.
Early detection and persistent treatment are vital for effective thrips control. Combine different eco-friendly methods like insecticidal soap, sticky traps, and predatory insects to bring heavy infestations under control.
Pictures of Thrips Damage
Here are some pictures of typical thrips damage to help you identify if these sap-sucking insects are attacking your plants:
Thrips larvae infesting a Monstera deliciosa leaf.
Learning to properly identify and treat thrips is critical to save your plants from damage. Pay close attention to new growth and flowering plants where thrips often gather. Take prompt action at the first signs of infestation to control these destructive sap-feeding pests.
Look for thrips waste:
One of the most telltale signs of thrips is the dark deposits they leave behind, sometimes referred to as “thrips poop.” If you see tiny black spots combined with stippled or wrinkled leaves, it’s likely you have thrips.
Introduce or attract natural predators:
Natural enemies include minute pirate bugs, lacewings, parasitic wasps, ladybugs, predatory mites, and nematodes.
Mulch, plastic, or mesh that reflects light can interfere with thrips ability to locate plants.
Thrips: How to Identify & Control | House Plant Journal
FAQ
How do you know if a plant has thrips?
… hold a sheet of paper under your plant and gently tap a leaf– if thrips are present, they may fall onto the paper making them more easily identifiableNov 30, 2023
What can be mistaken for thrips?
Thrips, aphids, planthoppers, leafhoppers, and whiteflies are common pests of specialty crops that are often misidentified. Whether it’s tomatoes or squash, it’s important to know the differences between these insects and what it means to see them on or around your crops.
Why do I suddenly have thrips?
Sudden, drastic thrips damage or high numbers of adults on cards or plant taps can indicate a large number of thrips have blown or flown into your greenhouse from outside.
Do thrips eat houseplants?
There are over 7,000 species of thrips that could feed and damage a wide variety of plant species. Around 150 of these will target houseplants. Thrips will breed and lay eggs in the plant tissue on the host plant. They also feed off the sugars and sap within the leaves. All of this causes severe damage that will ruin the look of your indoor plants.
Do thrips kill plants?
Thrips are tiny, winged insects that do tremendous damage to plants. These common pests feed on the sap and juices of houseplants, garden plants, and greenhouse crops. Thrip infestations can damage plants so much that leaves lose color, and plants eventually die. Thrips are challenging to get rid of.
What plants are affected by thrips?
Thrip-borne plant diseases can affect greenhouse plants, garden plants, and houseplants. Thrips can damage roses, tomato plants, ornamental plants, monstera houseplants, orchids, fruit trees, and vegetables. Usually, insects in the family Thripidae cause the most damage to plants. What do Thrips Look Like?
What is western flower thrips?
The Western flower thrips is one variety of thrips that can cause extensive damage on over 500 species of plants. The Almanac Garden Planner – Use It Free for 7 Days! Plan your 2025 garden with our award-winning Garden Planner. Try Now Have you seen thrips damage on your plants?
How big do thrips get?
Most thrips measure about 1 – 2 mm long, making them difficult to spot. Other names for thrips include thunderbugs, thunderblights, corn lice, and corn flies. Thrips damage plants when feeding on the leaves and stems. Thrips have mouthparts that pierce soft plant tissue so they can suck plant juices.
How do thrips affect plants?
Thrips can cause a variety of damage to crops and ornamental plants, including: Stunted growth: They feed on the sap of plants, causing stunted growth, reduced yields, and deformities in fruits and vegetables.