Cabbage white caterpillars (imported cabbageworm, etc.)
PestButterfly larvae chew holes, often with frass (droppings) visible on leaves or in heads.
Often on
Brassicas: kale, broccoli, cabbage, arugula, mustard greens.
Symptom tags
Signs in the garden
- Irregular holes, especially between veins; frass pellets.
- Green or striped caterpillars on leaf undersides or in heads.
- Butterflies hovering near brassicas in daytime.
What often helps (general)
- Row cover after transplanting blocks egg-laying if edges are sealed.
- Hand-pick on small plantings; check developing heads.
- B.t. products (where legal for your crop) are a common option — always read the label.
When to escalate
If heads are unmarketable or you need organic certification specifics, use extension guidance for your state.