Caterpillar Host Plants
Overview
Caterpillars feed on an exceptionally wide range of horticultural crops. While many species have preferred hosts, others are highly polyphagous and readily move between vegetables, ornamentals, herbs and soft fruit.
Host-plant knowledge is valuable because it helps growers predict where infestations are most likely to develop, identify crop reservoirs and prioritise monitoring.
The greatest risk usually occurs during periods of active moth flight when eggs are laid directly onto suitable host plants.
Protected Vegetables
Protected crops are particularly vulnerable because warm temperatures often allow rapid caterpillar development.
Common hosts include:
Typical damage includes:
- holes in leaves
- flower feeding
- fruit feeding
- frass contamination
- damaged growing points
Brassicas
Brassicas are among the best-known caterpillar hosts.
Common examples include:
Typical pests include:
- Large White Caterpillar
- Small White Caterpillar
- Diamondback Moth
- Cabbage Moth
Inspect leaf undersides regularly for eggs and newly hatched larvae.
Soft Fruit
Several caterpillar species attack soft fruit throughout the growing season.
Frequently affected plants include:
Damage may include:
- chewed fruit
- damaged flowers
- feeding on developing berries
- contamination by frass
Tree Fruit
Fruit trees may host numerous moth larvae during spring and summer.
Examples include:
Inspect developing fruit clusters and young shoots during periods of moth activity.
Ornamentals
Many ornamental crops support caterpillar populations.
Important hosts include:
Damage is often cosmetic but may reduce plant quality below saleable standards.
Herbs
Herbs can also support caterpillars, particularly during warm summers.
Common hosts include:
Because herbs are harvested for foliage, even minor feeding damage can be commercially important.
Typical Symptoms by Crop
| Crop | Common symptoms |
|---|---|
| Tomatoes | Fruit feeding, foliage holes, frass |
| Peppers | Leaf chewing, flower damage |
| Lettuce | Skeletonised leaves, holes |
| Brassicas | Large irregular holes, windowing |
| Strawberries | Flower feeding, damaged fruit |
| Ornamentals | Cosmetic leaf damage, chewed petals |
Monitoring Priorities
Inspect:
- crop edges
- lower foliage
- leaf undersides
- growing points
- flowers
- developing fruit
- dense canopy
Look for:
- eggs
- newly hatched larvae
- feeding damage
- silk
- frass
Early detection dramatically improves biological control success.
Reservoir Plants
Caterpillars often survive on plants outside the main crop.
Potential reservoirs include:
- weeds
- volunteer crop plants
- old crop residues
- unmanaged ornamentals
- surrounding hedgerows
These areas can provide a continuous source of adult moths entering production crops.
Incoming Plant Material
Inspect new plants carefully for:
- eggs
- young larvae
- feeding scars
- rolled leaves
- silk
- frass
Quarantining incoming material reduces the likelihood of introducing hidden infestations.
Reducing Host-Plant Risk
Useful IPM practices include:
- regular crop inspections
- weed management
- removing heavily infested plant material
- encouraging natural enemies
- protecting biological-control programmes
- monitoring adult moth activity
- acting while larvae remain small
Related Pages
- Caterpillars
- Caterpillar Identification Guide
- Caterpillar Environment & Risk Factors
- Caterpillar Life Cycle
- Caterpillar Damage Symptoms
- Plant Database
- Caterpillar biological control solutions
Key Message
Most caterpillar outbreaks begin on suitable host plants long before serious feeding damage becomes obvious.
Knowing which crops are most attractive to caterpillars allows monitoring and biological control to begin before significant economic damage occurs.