As major insect pests of many crop and ornamental plants, leaf miners tunnel their way through a wide range of plant species. With over 300 species of leaf miners worldwide, there are five considered to be serious horticultural pests:
- Vegetable leaf miner (Liriomyza sativae)
- Tomato leaf miner (Liriomyza bryoniae)
- Chickpea leaf miner (Liriomyza cicerina)
- Serpentine leaf miner (Liriomyza huidobrensis)
- American serpentine leaf miner (Liriomyza trifolii)
Leaf miners are tiny greyish black flies whose larvae cause damage by meandering a track under the surface of the leaf while feeding on leaf tissue. Additional, though lesser damage, is caused through puncture wounds from the adult feeding and depositing eggs just under the surface of the leaves.
Liriomyza sativae, the vegetable leaf miner, is native to the Americas but has spread to most parts of the world. It has established in the Torres Strait region.
See if you can identify the pest
Adult leaf miners are small, greyish black flies. They have a yellow and black body and are 1.3-2.3mm in length. The different species vary in colour which makes them identifiable. Adult females are larger than males and more robust.
The larval stage of the leaf miner is not usually seen as they remain inside the leaf tissue. Egg laying punctures can be seen as white speckles on leaves. The feeding track is white, often with an obvious trail of dark waste material inside. Damage caused by the leaf miner reduces the growth and development of seedlings and young plants which can lead to death.
Leaf miners can spread quite easily either by flying, wind dispersal or through the movement of infested plants soil or packaging.
If you work around imported goods you need to look for leaf miners or the damage they cause to leaves.
Growers and home gardeners
The host range for the different species is quite broad:
- Tomato leaf miner – many vegetables, mainly tomatoes
- Chickpea leaf miner – legumes, mainly chickpeas
- Serpentine leaf miner – 15 plant families, including beet, spinach, peas, beans, potatoes and cut flowers
- Vegetable leaf miner – 40 hosts in 10 plant families, including capsicum, melon, cucumber, carrot, lettuce
- American serpentine leaf miner – 28 plant families, including soyabean, cotton, pea, potato, aubergine
Keep a look out in your vegetable garden for these pests.
Check what can legally come into Australia
All Australians and international tourists have a role to keep out exotic pests and diseases.
Australia remains free of this exotic pest. We need your help to keep it this way.
Check what you can and cannot bring into Australia, whether you are a:
Keep vegetables off the menu for leaf miners
Leaf miners can quickly establish into most crops and can affect them at any part of their growth stages.
Import restrictions and biosecurity measures
Some items, by law, are subject to certain import conditions to be allowed into Australia. Please check the Biosecurity Import Condition System (BICON).
Be aware of any leaf miner biosecurity measures that may be in place for incoming goods and conveyances. Industry advice notices are reviewed regularly and could change.
Secure any suspect specimens
Containment is critical.
Alert the department if you see tracks in the leaves of castor oil plants or vegetables such as tomatoes, pumpkins, lettuce or melons.
Report detections of exotic pests
Any detections of leaf miners must be reported to the authorities.
If you receive or work around goods imported from overseas, including mail, you need to be vigilant to leaf miners and other exotic pests. If you see an unusual pest, secure the goods to limit the movement of the pest and immediately report it to the Department of Agriculture and Water Resource’s SEE. SECURE. REPORT. Hotline on 1800 798 636 or by using the online form.
Growers and home gardeners
If you see a leaf miner or anything unusual, report it to the Exotic Plant Pest Hotline 1800 084 881. This will put you in touch with the department of primary industries or agriculture in your state or territory.
When reporting your concern, you will be given advice on handling the specimen and what to do next until an officer can investigate.