Thrips tabaci

Larvae at base of onion leaf. Image: Whitney Cranshaw, Colorado State University, Bugwood.org

  • Onion thrips affects a wide range of plants including onions, garlic, leeks, shallots, horseradish, daisies, cotton and Cucurbitaceae species.
  • A complete generation requires 3-4 weeks during the summer months. Five to eight generations may occur each year. Adults have a yellow and brown body (<2mm long) with two pairs of hairy wings. They spend the winter in protected sites under plants and debris in onion fields and fly readily when disturbed.
  • Eggs are white to yellow in colour, kidney-bean shaped and microscopic in size. They develop within leaf tissue with one end near the leaf surface.
  • Stage 1 and 2 larvae are <1mm in length and are the active, feeding stages. They are white to pale yellow, with a long, thin body. They resemble adults without wings.
  • Damages leaves, bulbs, flowers.
  • Water loss through the damaged leaf surface may cause stress and reduced plant growth. Onions are most sensitive to thrips injury during the rapid bulb enlargement phase. Fast plant maturity due to thrips injury may shortened the bulb growth period. Following harvest and during storage, thrips may continue to feed on onion bulbs, causing scars that reduce quality and visual appearance of bulbs.
  • Spread through infested plant material. Adults can fly.
Scientific name: Thrips tabaci (exotic strains/biotypes)
EPPRD Category:
Life Form: Thrips (THYSANOPTERA)

Pest Documents

FS: fact sheet

CP: contingency plan

DP: diagnostic protocol