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.