Symptom · 1 possible cause
Winding pale trails in leaves
Serpentine tunnels lengthen and widen as the larva feeds inside the leaf..
- Also called
- leaf miner trails
- squiggly lines on leaves
- tunnels in leaves
- snake trails on leaves
Likely causes, most likely first
Ranked for this sign on its own. Your stage, medium and readings change the order, so run the checker for your plant.
PossibleLeafminers
Fix: Pinch mined leaflets and the larva inside; yellow cards for adults; parasitoid wasps (e.g. Diglyphus) in greenhouses. Cosmetic in light infestations.
Recovery: No new mines after 2 weeks.
How to confirm it
- Magnifier check of leaf undersides and new growth. Use a 10-20x loupe for spider mites, thrips, aphids and whiteflies, and a 30-60x lens or clip-on phone macro for broad and russet mites. Check the undersides of 10 affected leaves across several plants and the newest shoot tips, in white light. Look for moving dots, eggs, shed skins, webbing, slender insects with black specks, and glassy specks on new growth.
Look for
Pale winding mines with a dark line of frass inside and a larva at the wide end..
The full guide: Spots, brown patches and dead edges on cannabis leaves: the master decision tree
Guidance, not a guarantee. The checker weighs common causes against what you tell it; confirm with the tests before you treat, change one thing at a time and watch the new growth.
