# White cottony or waxy clumps in leaf axils and stems: likely causes and fixes

> White cottony or waxy clumps in leaf axils and stems on cannabis is most often Mealybugs. How to tell them apart, the fix for each and what recovery looks like.

Also called: white fluff on stems, cotton balls on plant, white waxy bugs, mealybugs.

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

## Likely causes, most likely first

### Mealybugs (Possible)

- Kind: Pest; urgency: Deal with it this week
- Fix: Remove colonies with a cotton bud dipped in 70% isopropyl alcohol (veg only, test a leaf first); release mealybug predators (e.g. Cryptolaemus beetles) or parasitoids; quarantine new stock; discard heavily infested plants.
- Recovery: No new cottony clusters 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: [Mealybugs and root mealybugs on cannabis: ID, life cycle in numbers and IPM](https://genetixbay.com/knowledge/pests/mealybugs.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.