# Winding pale trails in leaves: likely causes and fixes

> Winding pale trails in leaves on cannabis is most often Leafminers. How to tell them apart, the fix for each and what recovery looks like.

Also called: leaf miner trails, squiggly lines on leaves, tunnels in leaves, snake trails on leaves.

Run the checker with this sign: https://genetixbay.com/knowledge/diagnose/?at=whole&s=leaf-trails

## Likely causes, most likely first

### Leafminers (Possible)

- Kind: Pest; urgency: Low urgency
- 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.
- Confirm: 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.
- Article: [Spots, brown patches and dead edges on cannabis leaves: the master decision tree](https://genetixbay.com/knowledge/diagnosis/spots-necrosis-decision-tree.md)

## Note

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.