Whitefly Host Plants
Overview
Whiteflies feed on a wide range of vegetables, ornamentals, fruit crops and weeds.
Host range varies between species:
- glasshouse whitefly is especially important in protected vegetables and ornamentals
- tobacco or silverleaf whitefly has a very broad host range
- cabbage whitefly is mainly associated with brassicas
Risk is generally highest in warm, continuously cropped systems with dense foliage and weak lower-leaf monitoring.
Main protected-crop hosts
Whitefly is particularly important on:
- Tomato
- Cucumber
- Sweet Pepper
- Chilli Pepper
- Aubergine
- Poinsettia
- Fuchsia
- Pelargonium
- Chrysanthemum
- Rose
- Strawberry
- Basil
These plant records also show the other pests commonly associated with each crop.
Brassica hosts
Cabbage whitefly is commonly associated with:
Colonies usually develop on leaf undersides and may produce heavy wax, honeydew and sooty mould.
Other linked hosts
Additional hosts currently represented in the Plant Database include:
Typical symptoms by crop
| Crop group | Typical warning signs |
|---|---|
| Tomato | Adults on lower leaves, nymphs, honeydew and yellowing |
| Cucumber | Dense lower-leaf colonies and sticky foliage |
| Pepper and chilli | Adults, nymphs, reduced vigour and contamination |
| Aubergine | Lower-leaf colonies, yellowing and honeydew |
| Poinsettia | Adults disturbed from foliage and hidden immature stages |
| Ornamentals | Cosmetic contamination, honeydew and sooty mould |
| Brassicas | Waxy colonies beneath leaves and heavy contamination |
| Soft fruit | Sticky foliage and localised lower-canopy colonies |
Why lower leaves matter
Whiteflies commonly establish on older foliage because:
- adults settle and lay eggs on leaf undersides
- immature stages remain attached to the leaf
- lower leaves are often inspected less frequently
- dense canopy protects developing colonies
- old foliage can become a persistent pest reservoir
Monitoring only the top of the crop can miss an established infestation.
Incoming plant material
Inspect incoming plants for:
- adults flying when foliage is disturbed
- eggs on young leaf undersides
- scale-like immature stages
- honeydew
- sticky leaves
- black sooty mould
- previous pesticide residues that may disrupt parasitoids
Suspect material should be isolated before it enters the main crop.
Weed and carryover hosts
Whitefly populations can persist on:
- weeds beneath benches
- volunteer crop plants
- retained stock plants
- old crop material
- ornamentals around production areas
- continuously cropped compartments
Removing the crop without dealing with these reservoirs may not break the pest cycle.
Host-plant monitoring
Inspect:
- lower and older leaves
- crop edges
- warm bays
- areas around doors and vents
- carryover plants
- incoming stock
- weeds
- plants with honeydew or sooty mould
Use sticky traps to track adult movement, but confirm population development by inspecting the crop.
Reducing host-plant risk
Useful actions include:
- starting biological control early
- removing heavily infested lower leaves where appropriate
- maintaining regular crop scouting
- controlling weeds
- avoiding unnecessary crop carryover
- cleaning up old plant material
- protecting parasitoids from disruptive pesticides
- confirming the whitefly species where programme choice depends on it