# Droppings (frass), webbing or holes in buds: likely causes and fixes

> Droppings (frass), webbing or holes in buds on cannabis is most often Caterpillars and budworms. How to tell them apart, the fix for each and what recovery looks like.

Also called: poop in buds, frass, caterpillar in bud, black pellets in buds, bud eaten from inside.

Run the checker with this sign: https://genetixbay.com/knowledge/diagnose/?at=buds&s=frass-in-buds

## Likely causes, most likely first

### Caterpillars and budworms (Likely)

- Kind: Pest; urgency: Act within a day or two
- Fix: Hand-pick; exclude moths with netting; use Bt (kurstaki or aizawai) while larvae are small, since it must be eaten and breaks down in sunlight in days. Remove bored buds: frass starts bud rot.
- Recovery: No fresh frass or holes after 1 week.
- Confirm: Open the densest colas: In flower, gently spread the largest, densest colas at the base and look for brown, mushy or grey tissue around the stem, a single wilted sugar leaf that pulls out easily, frass or caterpillars. Check 5-10 colas per plant each week from mid-flower, more when RH is high. Bag any rot before removing it.
- Article: [Caterpillars on cannabis: species, degree-days and control](https://genetixbay.com/knowledge/pests/caterpillars.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.