Thrips Host Plants
Overview
Thrips attack a wide range of horticultural crops, but damage severity varies between plant species, crop stages and production systems.
Risk is generally highest where crops are:
- flowering
- producing soft new growth
- grown under warm protected conditions
- maintained for long periods
- difficult to inspect closely
- exposed to incoming plant material or nearby weed hosts
Different thrips species also have different host preferences.
High-risk protected crops
Thrips are particularly important in:
Flowering crops often support faster thrips population growth because pollen provides an additional food source.
Outdoor and allium crops
Important outdoor hosts include:
Onion thrips can remain hidden within tight leaf folds, making direct plant inspection essential.
Symptoms by crop
| Crop | Typical thrips symptoms |
|---|---|
| Strawberry | Flower injury, bronzed fruit, seed haloing and scarring |
| Sweet pepper | Flower damage, fruit scarring and leaf silvering |
| Chilli pepper | Distorted growth, flower damage and fruit marking |
| Cucumber | Silver streaking, distorted young leaves and reduced quality |
| Aubergine | Leaf silvering, bronzing and flower injury |
| Tomato | Leaf and flower damage, with virus risk in susceptible systems |
| Chrysanthemum | Flower damage, petal marking and distorted growth |
| Rose | Petal browning, flower distortion and cosmetic loss |
| Onion and leek | Silver streaking and feeding within leaf folds |
| Herbs | Leaf scarring and contamination of saleable growth |
Flowering crops
Flowering crops are often at higher risk because thrips:
- feed within flowers
- use pollen as food
- remain hidden between petals
- reproduce rapidly under warm conditions
- can damage flowers and developing fruit before adults are easily detected
Flower tapping over white paper or a tray is one of the most useful monitoring methods.
Leaf-focused thrips
Some thrips species concentrate more heavily on foliage than flowers.
Typical symptoms include:
- leaf silvering
- bronzing
- black faecal spots
- lower-canopy hotspots
- feeding on leaf undersides
See:
Crop-stage risk
Young vegetative growth
Inspect:
- growing points
- folded young leaves
- soft flushes of growth
- propagation material
Flowering
Inspect:
- flowers
- pollen areas
- petals
- developing fruit
Fruit development
Look for:
- bronzing
- russeting
- surface scarring
- uneven colour
- fruit distortion
Monitoring priorities
A strong host-plant monitoring programme includes:
- flower tapping
- direct inspection of young leaves
- sticky-trap trend monitoring
- recording hotspots by row or bay
- inspecting incoming plants
- checking weeds and crop margins
- distinguishing flower thrips from leaf thrips
Trap catches should be interpreted alongside crop inspections and visible damage.
Reducing host-plant risk
Useful actions include:
- introducing predatory mites preventatively
- using Orius where crop and flowering conditions support establishment
- removing severe hotspots
- controlling weed reservoirs
- inspecting incoming plants
- maintaining predator continuity
- avoiding disruptive pesticide use
- removing old flowers and crop debris where practical