Allium Leaf Miner (Phytomyza gymnostoma)
Leafmining pest of leeks, onions and other alliums causing distorted foliage and rotting stems.
Allium leaf miner (Phytomyza gymnostoma) has become a serious pest of leeks, onions and garlic in the UK. Adult flies lay eggs in characteristic rows of punctures; larvae tunnel in the leaves and stems, leading to distortion, rot and secondary infections. Cultural control (fleece, timing of planting, removal of infested material) is critical. Biological control focuses on soil-applied entomopathogenic nematodes targeting pupae and larvae in the base and surrounding soil.
Biological Controls for Allium Leaf Miner (Phytomyza gymnostoma)
The species below are examples of beneficial organisms commonly used against allium leaf miner (phytomyza gymnostoma). Recommendations are based on published biological control information and practical IPM experience. Always confirm suitability for your crop, growing system and local conditions before use.
Diglyphus isaea
Environment: outdoor
Temperature Range: 10.0 – 25.0°C
Rate: 0.25–1 wasp/m² in protected or covered crops
Frequency: Weekly during main mining period
Can contribute where alliums are grown under protection or covers; combine with netting and crop hygiene.
Further BioWiki Reading
For more background on pest biology, beneficial insects and environmental factors, use the BioWiki alongside this practical control guide.
Related Biological Solutions
Growers dealing with allium leaf miner (phytomyza gymnostoma) often also monitor these pests as part of a complete IPM programme: