Whitefly
Trialeurodes vaporariorum
Tiny white-winged sap-suckers that swarm up in clouds when foliage is disturbed. Transmit serious viruses.
Not sure it is Whitefly? Photograph it. Every member gets a free Plant Check, one answer for one photo. Pro includes 20 photo checks each month.
Identify from a photoBackground
Two whitefly species matter in Australian vegetable gardens. Silverleaf whitefly (Bemisia tabaci) is a major pest of warm-climate crops and a known vector of tomato yellow leaf curl virus and several cucurbit viruses. Greenhouse whitefly (Trialeurodes vaporariorum) is more common in cooler regions and in protected cropping.
Both species feed on leaf undersides, excrete honeydew and cause black sooty mould. Heavy infestations stunt and weaken plants; virus transmission is often the most damaging consequence.
How to identify
- Adults: 1-2mm, moth-like, bright white, held tent-wise at rest
- Nymphs: flat, scale-like, translucent, on leaf undersides
- Silverleaf whitefly adults hold wings closer to the body and look pointier than greenhouse whitefly
- Damage: yellowing leaves, stickiness and sooty mould; for silverleaf on cucurbits, silvering of upper leaf surface; virus symptoms (leaf curl, mosaic)
Life cycle
Egg to adult in 3-5 weeks at warm temperatures. Continuous overlapping generations in heated greenhouses and subtropical gardens.
Weather triggers
- Temperature: 15-35°C
- Populations explode in warm dry weather. Silverleaf whitefly continues breeding through mild winters in the subtropics.
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
- Yellow sticky traps placed amongst plants catch adults and monitor populations
- Horticultural oil or soap sprays applied to leaf undersides every 5-7 days
- Release of parasitic wasp Encarsia formosa in greenhouse settings
- Remove heavily infested lower leaves
Chemical control
- Resistance to synthetic insecticides is widespread in silverleaf whitefly. Rotate active ingredients if using them
- Home gardeners should rely on oils, soaps and biological control rather than chemical sprays
Always read product labels. Registrations change.
Prevention
- Inspect seedlings before planting. Whitefly is often introduced on nursery stock
- Remove old crop residues promptly
- Avoid growing tomato, capsicum and cucurbit crops back-to-back in the same bed
Companion planting
Basil is widely reported to deter whitefly in tomato beds; evidence is mixed. French marigold (Tagetes patula) confuses host-finding and attracts predators.
Biosecurity
Resistant strains of silverleaf whitefly (biotype B and Q) are a concern in commercial cropping.
Know when Whitefly is actually about
The calendar above is the season. It cannot tell you what is happening in your street this week. Get the free weekly email, or see live pressure for your own postcode on Pro.
The free weekly garden email
One email a week: what to plant, what to harvest, and what to watch for in your climate zone. Free, and you can stop it in one click.
Live pest pressure, for your postcode
The season tells you it is possible. This tells you it is happening.
- Risk scored for your own postcode, next 7 days
- Queensland fruit fly tracking
- GardenBuddy.au Check: photograph it, get it identified, 20 photo checks each month
- Weekly Pest Alert matched to your zone, season and crops
$59 a year or $7.99 a month. Every paid plan starts with a 30 day free trial. Cancel any time.
Just this one problem? Every member gets a free Plant Check, one photo, one answer.