closeup of thrips

Western flower thrips nymph
Whitney Cranshaw, Colorado State University, Bugwood.org

Updated: March 26, 2021

Signs and symptoms of thrips on indoor plants

  • Thrips are very tiny insects, 1-2mm long. They are slender with narrow wings fringed with hairs. They may be white, yellow, brown or black.

  • The immatures are smaller and usually white or yellow.

  • There are several generations.

  • Some species overwinter in the soil; others die in winter are replaced in the spring by populations migrating in from the south.

  • Some thrips may feed on only one plant species, while others are general feeders on the flowers and leaves. Some thrips species feed only on pollen and cause no damage.

  • Others suck plant juices in a linear pattern that looks like irregular white streaks and give a silvery appearance to damaged leaves. Some species may deposit minute black fecal spots on leaves.

  • On flowers, damage appears as white or brown blotches.

     

    white thrips damage on a pink flower
    Scarring injury on flower petals
    Photo: Whitney Cranshaw, Colorado State University, Bugwood.org

Management strategies

  • Thrips generally do not require control in the home. They are usually brought in on infested plants.

  • Dispose of severely damaged plants.

  • Western flower thrips damage on verbena leaves
    Photo: Chazz Hesselein, Alabama Cooperative Extension System, Bugwood.org

    HGIC_IndoorPlants_Thrips_damage_400
  • Daisy flower damaged by thrips
    Photo: Whitney Cranshaw, Colorado State University, Bugwood.org

    Thrips damage on daisy flower