Tomato Spotted Wilt Virus (TSWV)
Tomato spotted wilt orthotospovirus
Thrips-transmitted virus that causes bronzing, stunting and fruit distortion on tomatoes, capsicums and lettuce.
Background
TSWV is one of the most damaging plant viruses worldwide. It is transmitted only by several thrips species, most importantly western flower thrips. Once infected, individual plants cannot be cured; management is about keeping thrips and their weed hosts under control before the plant is infected.
How to identify
- Bronze or coppery discolouration on leaves, particularly the apical growth
- Ringspots and yellow mottling on leaves
- Distorted stunted growth
- Fruit with concentric ringspots or sunken discoloured areas
Life cycle
Virus acquired by thrips only as larvae. Adult thrips then transmit for life. Many alternate weed and ornamental hosts maintain the virus reservoir.
Weather triggers
- Temperature: 15-35°C
- Aligned with peak thrips activity in warm dry weather.
Peak season (southern hemisphere)
Red = active season · Dark red outlined = this month
Affected vegetables & crops
Click any crop to see current prices and growing info.
Climate zones at risk
Organic & low-impact control
- No treatment — remove infected plants immediately and destroy
- Control thrips with blue sticky traps, spinosad and reflective mulches
- Weed control to remove virus reservoirs
Chemical control
- No chemical cure for the virus
Always read product labels — registrations change.
Prevention
- Plant resistant tomato cultivars where available
- Inspect nursery seedlings — do not plant any showing bronzing or ringspots
- Manage thrips populations around the crop
- Weed control, especially of sowthistle and other reservoir hosts
Companion planting
No direct companion effect.
Biosecurity
Widely established. New resistance-breaking strains occasionally reported.
Sources
- Agriculture Victoria — Tomato spotted wilt virus
- NSW DPI — TSWV in tomatoes and capsicums
Accuracy confidence: high. We update this library as new extension guidance is published.