Field Identification
Agromyzid fly whose larvae mine leaves of beans, cucurbits, peppers, and many leafy greens, leaving blotchy or serpentine tunnels and reducing photosynthetic area. Often worse in warm seasons and irrigated, high-nitrogen plantings.
Small yellow-and-black adults; larvae are translucent maggots visible when you hold mined leaves to the light. Heavy mining can cause leaf cupping and premature drop; damage is often concentrated on the newest growth.
How to Deal With It
Organic Control Methods
Neem, insecticidal soap, or spinosad-based OMRI-listed products directed at adults and young mines—repeat on a short interval while flights continue, with attention to leaf undersides.
Parasitoid wasps in the Diglyphus and Chrysonotomyia groups commonly recycle populations in unsprayed plantings; flowering insectary strips help maintain them.
Strip mined leaves on small plants; rotate away from susceptible hosts; avoid over-fertilizing with quick-release nitrogen that pushes soft, attractive foliage.
Floating row cover excludes adults from seedling beds; yellow traps for monitoring and mass-trapping in tunnels or greenhouses.
Start clean transplants; rogue reservoir weeds in the aster family and other agromyzid hosts near fields.
Let Nature Handle It
Natural Enemies
- Diglyphus spp.
- Chrysonotomyia spp.
- Green Lacewings