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Thrips

Confirm slender insects alongside fresh scarring before treating. Thrips include plant feeders and predators, and old silvered leaves will not recover after insects are gone.

Latest source check 15 October 2026Source-led field guide
Make an action plan

Match the organism, its setting and its signs. A photograph or a single symptom cannot confirm every species or cause.

Western flower thrips on a leaf
Photographed exampleWestern flower thrips on a leaf.Frankliniella occidentalis
Identification limits & photo credit

Magnified winged specimen; species identification requires finer examination than a garden photograph. The plant is unspecified and the image does not distinguish feeding damage from other causes.

Western flower thrips on a leaf. Photo: Frank Peairs, Colorado State University, Bugwood.org. CC BY 3.0. Original source · CC BY 3.0 & details

01 / IdentifyCheck the evidence ↗02 / RespondChoose the next step ↗03 / Follow throughKnow what to check ↗
In this guide
Your first decision

Tolerate cosmetic injury where possible

Keep vigorous plants with limited damage under observation. Compare new growth rather than removing all marked foliage.

Sources for this section

University of California Statewide IPM Program · UC Statewide IPM Program · US Environmental Protection Agency

01 / Identify

Recognize the signs

Insects
Very small, slender insects; adults have narrow fringed wings visible with magnification. Tap a flower or leaf over white paper to make movement easier to see.
Feeding evidence
Silvering, scarring, distorted new growth and small dark faecal specks can accompany feeding, but none identifies a species alone.
Sources for this section

University of California Statewide IPM Program

Differences that change the decision

A similar-looking organism can need a different response. Compare the evidence and what it changes.

Compare every column. On a narrow screen, scroll the table sideways.

TypeWhat to checkWhat changes
Flower-feeding thripsFound in blossoms, buds or tender tissue; some species also transmit plant viruses.Inspect fresh flowers and buds, not just already scarred leaves. Disease symptoms need a plant clinic.
Greenhouse thripsOften associated with leaf surfaces on susceptible ornamental hosts.Check sheltered foliage and local host guidance; some outdoor populations are suppressed by parasitoids.
Predatory thripsSome thrips feed on mites or other insects rather than damaging plants.Do not treat every slender insect as a pest. Ask for identification if damage and observed insects do not agree.
Sources for this section

University of California Statewide IPM Program · UC Statewide IPM Program

What else could it be?

Spider mites

Stippling and bronzing overlap; examine for mites and fine webbing.

Compare spider mites

Leafhoppers and other sap feeders

Their bodies and movement differ, but feeding marks can overlap.

Compare plant bugs & leafhoppers

Weather, chemical or disease injury

Damage without feeding insects requires a broader plant-health check.

Compare plant disease & stress
Sources for this section

University of California Statewide IPM Program · Virginia Cooperative Extension

Inspect the right places

  1. Sample injured and healthy tissue

    Use a hand lens and white paper. Record insect shape, affected plant part, host and whether new damage is developing.

  2. Check protected growth

    Unfold a sample bud or examine leaf undersides without stripping the plant. A few adults on a sticky card do not locate larvae or establish the cause.

Sources for this section

University of California Statewide IPM Program · Virginia Cooperative Extension

02 / Respond

Choose a proportionate response

For pesticides, the local product label determines the allowed pest, site, precautions and timing. Check safety and regional guidance.

  1. Tolerate cosmetic injury where possible

    Keep vigorous plants with limited damage under observation. Compare new growth rather than removing all marked foliage.

  2. Reduce local sources

    Prune a small number of badly affected shoots where appropriate; manage dusty conditions and plant stress. Protect predators and parasitoids.

  3. Seek a targeted option for continuing injury

    Thrips hidden inside buds may escape contact products. Local advice should consider species, host, flowering, beneficial insects and a label that permits the use.

Turn these steps into your own checklist ↗
Sources for this section

University of California Statewide IPM Program · UC Statewide IPM Program · US Environmental Protection Agency

Avoid these mistakes

  • Do not repeat broad sprays because old scars remain.
  • Do not assume yellow sticky catches prove a damaging species or a virus.
  • Do not use insecticide as a cure for an established plant virus.
Sources for this section

University of California Statewide IPM Program

03 / Follow through

Check whether it is working

When to look again

Suggested practice: inspect the same fresh growth and flowers every few days during active damage; follow labelled intervals if a product is used.

Evidence of progress

Less fresh scarring or distortion and lower counts of plant-feeding thrips. Existing scars remain.

Record an observation ↗

Get help when…

  • Persistent bud loss, stunting or suspected virus: local plant diagnostic service.
  • Greenhouse or valuable plant collection with repeated failure: horticultural pest specialist for species and resistance advice.
Prepare for a professional inspection ↗
Sources for this section

University of California Statewide IPM Program · Virginia Cooperative Extension

Prevent a return

  • Inspect new plants, especially flowers and tightly folded growth.
  • Support beneficial insects and avoid unnecessary persistent sprays.
Sources for this section

UC Statewide IPM Program

Common questions

Can I identify thrips from a silver leaf?

No. The leaf directs inspection; a specimen, host and fresh damage are needed to narrow the diagnosis.

Why does treatment seem to have failed?

Old marks persist, hidden stages may remain, or the cause may be different. Recheck fresh tissue before changing products.

Sources for this section

University of California Statewide IPM Program

Check the evidence

Sources & scope

References retain their geography and dates. A source-check date is not a claim of independent specialist review.

  1. Thrips

    University of California Statewide IPM Program. California, United States; host, climate and local species matter; source date 2014-05; source check, not expert review Checked 2026-10-15.

  2. Biological Control and Natural Enemies of Invertebrates

    UC Statewide IPM Program. California, United States; biology may transfer, management timing and permitted products require local verification; source check, not expert review Checked 2026-10-15.

  3. Spider Mites

    University of California Statewide IPM Program. California, United States; host, climate and local species matter; source date 2011-12; source check, not expert review Checked 2026-10-15.

  4. Diagnosing Plant Problems

    Virginia Cooperative Extension. Virginia, United States; general diagnostic method; source date 2023-11 review; source check, not expert review Checked 2026-10-15.

  5. Do's and Don'ts of Pest Control

    US Environmental Protection Agency. United States; source check, not expert review Checked 2026-10-15.

Individual medical or veterinary diagnosis, structural assessment, uncertain species identification and local treatment permissions require the appropriate professional. About our editorial process.

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