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Thrips

Characteristics:

  • Eggs: Females lay their eggs on top of or on the inside of green plant parts, usually leaves.
  • Nymphs: Nymphs are translucent white to yellow in colour. They are extremely small and slender with a long abdomen and immature wings. After hatching, nymphs emerge from the egg site and begin eating the plant.
  • Adults: Adult thrips are shiny, yellow or black in colour and are less than 1.5 mm long. Both sets of wings are long, narrow, and edged with long ‘fringes’.

Identifying infestations:

  • Silvery-white lesions on leaf surfaces: Thrips use their rasping and sucking mouthparts to scrape the leaf surface and suck plant sap. This feeding action causes silvery-white, mottled lesions to appear on the leaf surface.
  • Thrip colonies: Although extremely small, you can see thrip colonies using a hand lens or magnifying glass.
  • White or straw-coloured plants: Large thrip populations can cause such severe damage that the entire plant can appear white or straw-coloured.

IPM Toolkit:

  • Preventive tools:
    • Follow a regular watering, fertilizing, and pruning schedule to keep your trees as healthy as possible to resist attack.
    • Watch for thrip infestations during warm weather which encourages faster growth cycles.
    • Keep your yard clean by removing organic debris and weeds where thrips can live.
  • Physical tools: Not applicable
  • Biological tools: Not applicable
  • Least toxic chemical tools:
    • Apply insecticidal soap according to label directions to control early infestations.