PEST MANAGEMENT DECISION GUIDE: GREEN LIST
Whiteflies on tomato
- Remove tomato residues and volunteer tomatoes and bury or burn
- Plant varieties which are resistant to whitefly and the viruses it can transmit, if available
- Plant tomatoes 0.5-2 feet apart with at least 3 feet between rows
- Use a shade net (size 400 µm) / tunnel for 3-5 weeks while in nursery to prevent attack by white flies
- Transplant shortly after or during the rainy season
- Use white/black inert plastic mulch 10-20 days after transplanting which attracts and kills white flies
- Conserve natural enemies (wasps, ladybirds) by mulching or leaving a natural hedge of flowering plants (e.g. Tithonia, Lantana) along the edges to offer them refuge
- Plant repellent crops such as coriander or Mexican marigold after 3-4 rows of tomato to repel the whiteflies
- Keep the field weed-free throughout the cropping season since weeds act as alternate hosts and can harbour whitefly-transmitted viruses
- Adult: A sucking insect, about 1 mm long. The body and wings are covered in a powdery, waxy secretion, white to slightly yellowish in colour
- Larva: yellow-white scales, 0.3-0.6 mm long
- Puparium: flat, irregular, oval shape, 0.7 mm long
- After transplanting monitor weekly until harvest
- Search for leaves with whitefly groups (they are mainly on underside of leaves). They will fly when you shake plants.
- Yellowing, curling, crumpling of leaves occurs at heavy infestation.
- Whiteflies can transmit viruses which cause virus disease. Leaves will have yellowish green mosaics
- Action threshold level is 10-20 plants with symptoms and/or at least 20 whiteflies on at least 10-20 plants/acre
- Use yellow sticky traps at about 1 per 5 plants.
- Spray biopesticide Beauveria (check product labels for dosage and application timing). After 21 to 28 days, next application if needed. Another entomopathogenic fungi that white fly is suscptible too is Lecanicillium lecanii
- Use hot pepper spray at rate of 30 chopped peppers in warm water. Soak for 1 day, dilute in 10 L water and add 20 drops of liquid soap before spraying
- Spray Azadirachtin 0.03% (50 ml/20L water) 15 days after transplant
- Use liquid soap spray at rate of 3 table spoons per litre of water
- Conserve natural enemies. Several wasps, including species in the Encarsia and Eretmocerus genera, parasitize whiteflies. Whitefly nymphs are also preyed upon by bigeyed bugs, lacewing larvae, and ladybird larvae.
CREATED/UPDATED: April 2017
PRODUCED BY: Plantwise
©CAB International. Published under a CC-BY-SA 4.0 licence.