Western Flower Thrips

    Western Flower Thrips

    Frankliniella occidentalis

    flower thrips

    Western flower thrips and varnish-like excrement  (David Cappaert, Bugwood.org)

    thrips damage

    Flower thrips damage (Chazz Hesselein, Alabama Cooperative Extension System, Bugwood.org)

    flower thrips damage

    Flower thrips damage (Bruce Watt, University of Maine, Bugwood.org)

    Pest Description

    • adults: very tiny, ~ 1/16 inch; elongated and yellowish to dark brown
    • fringed wings visible under magnification
    • nymphs: smaller and yellowish; wingless

    Host Plants, Diet & Damage

    • many herbaceous plants and flowers; fruits; vegetables; few ornamentals
      feed on plant sap and pollen
    • cause yellow/bronze stippling; cupping; leaf browning and dieback
    • may cause premature leaf drop and plant death
    • can damage flowers and fruit
    • can transmit diseases
    • leave tiny black varnish-like fecal spots on leaves

    Biology, Life Cycle & Damaging Life Stage

    • overwinter as adults in debris around host plants
    • adult activity begins in spring around budbreak
    • eggs laid inside leaf and bud tissue
    • eggs hatch in about 1 week; first two nymph stages (and adults) feed on plant tissue, pollen and nectar
    • pre-pupae and pupal stages develop in the soil
    • many generations per year; continuous indoors
    • immatures and adults are the damaging stages

    IPM Recommendations

    • Manage plants to improve or maintain health.
    • Monitor thrips populations on host plants with a “paper test” or visual inspection.
    • Preserve beneficial mites and organisms.
    • Apply an insecticide (azadirachtin; horticultural oil; insecticidal soap; neem oil; pyrethroid; spinosyn) when monitoring indicates it is necessary.

    For more information, see our Western Flower Thrips fact sheet.