Leafminer Host Plants
Overview
Leafminers attack a wide range of vegetables, herbs, ornamentals and allium crops.
The term “leafminer” covers several pest groups, including:
- agromyzid leafminer flies
- allium leafminer
- chrysanthemum leafminer
- pea leafminer
- tomato leafminer fly
- tomato leafminer moth (Tuta absoluta)
Host range differs between species, so crop association is useful when interpreting mine shape, season and likely pest identity.
Protected vegetables
Important protected-crop hosts include:
Typical symptoms include:
- serpentine mines
- blotch mines
- feeding punctures
- reduced leaf area
- premature leaf ageing
- lower crop quality
Tomato should be inspected especially carefully because both agromyzid leafminer flies and Tuta absoluta may occur.
Leafy crops
Leafminers are especially damaging where foliage is the harvested product.
Important hosts include:
Even light mining may reduce marketability.
Inspect:
- young leaves
- outer leaves
- newly expanded foliage
- crop edges
- plants near doors or vents
Herbs
Important herb hosts include:
Leaf damage is commercially important because the crop is sold for appearance and foliage quality.
Fresh mines may make otherwise healthy plants unmarketable.
Allium crops
Allium leafminer is especially associated with:
Typical signs include:
- lines of pale feeding punctures
- mines in leaves
- distorted growth
- larvae within stems
- brown pupae inside stems or bulbs
- secondary rotting
See:
Brassicas
Leafminers may occur on:
Damage is often less important than caterpillar feeding, but mining can reduce leaf quality and weaken young plants.
Check leaf undersides and fresh growth carefully.
Root and field vegetables
Linked hosts include:
Mining may reduce photosynthetic area and indicate nearby weed or volunteer reservoirs.
Legumes
Important linked hosts include:
Pea leafminer and related species may produce winding mines in foliage.
See:
Ornamentals
A major ornamental host is:
Visible mines reduce plant quality and marketability even where overall plant vigour remains acceptable.
Protected ornamental crops are at greater risk where:
- production is continuous
- incoming plants are not inspected
- parasitoids are disrupted
- old crop material remains nearby
See:
Typical symptoms by crop group
| Crop group | Typical symptoms |
|---|---|
| Protected vegetables | Serpentine or blotch mines, feeding punctures |
| Leafy crops | Visible mines and reduced marketability |
| Herbs | Cosmetic damage to saleable foliage |
| Alliums | Feeding punctures, mines, stem and bulb damage |
| Brassicas | Mines in foliage and reduced leaf area |
| Legumes | Winding mines and premature leaf ageing |
| Ornamentals | Cosmetic damage and crop rejection |
Young foliage risk
Many leafminer species prefer:
- young leaves
- actively growing tissue
- soft crop flushes
- propagation material
Fresh growth should receive extra attention because egg laying and new mines often begin there.
Incoming plant material
Inspect incoming stock for:
- fresh mines
- adult feeding punctures
- larvae inside leaves
- exit holes
- pupae
- adult flies on traps
Propagation plants can spread infestations between sites before symptoms become severe.
Weed and volunteer hosts
Potential reservoirs include:
- weeds beneath benches
- weeds around tunnels
- volunteer crop plants
- old crop residues
- unmanaged field margins
- discarded ornamental stock
Reservoir plants can maintain adults and larvae between crop cycles.
Crop-edge risk
Leafminer outbreaks often begin around:
- doors
- vents
- crop edges
- incoming plant areas
- warm sheltered bays
- weedy margins
These areas should be monitored more frequently than the centre of the crop.
Monitoring by host plant
Inspect:
- newest expanded leaves
- upper canopy
- lower leaves with old mines
- crop edges
- incoming plants
- weeds and volunteers
- yellow sticky traps
Record:
- number of fresh mines
- mine type
- adult trap catches
- evidence of parasitism
- recurring hotspots
Removing mined leaves
Removing mined leaves may help where:
- mines are fresh
- larvae are still present
- infestations are localised
- crop loss from leaf removal is acceptable
Avoid removing large numbers of leaves where parasitoid activity is already strong.
Check mines for signs of parasitism before disposal.
Biological control links
Important pages include:
Reducing host-plant risk
Useful practices include:
- inspecting incoming plants
- controlling weeds
- removing severe hotspots
- protecting parasitoids
- avoiding unnecessary broad-spectrum pesticides
- preventing crop overlap
- cleaning old crop material
- tracking fresh mines rather than old damage alone
Related pages
- Leafminer overview
- Leafminer Identification Guide
- Leafminer Environment and Risk Factors
- Leafminer Life Cycle
- Leafminer Damage Symptoms
- Commercial Leafminer Species
- Plant Database
- Leafminer biological control solutions
Key message
Leafminer risk is highest in crops with young, actively growing foliage and continuous plant availability.
Knowing the host crop helps narrow identification, target monitoring and protect parasitoid-based biological control programmes.