# Caterpillars on leaves or buds: likely causes and fixes

> Caterpillars on leaves or 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: caterpillars, worms on my plant, green worm, budworms.

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

## 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.