Entity scope
This profile centers on imported cabbageworm, Pieris rapae. Other caterpillars feed on brassicas.
Quick identity
- Scientific scope
- Pieris rapae
- Entity scope
- Species profile
- Broad form
- Velvety green caterpillar with faint pale lines; details change with growth.
- Useful clue
- The adult is a white butterfly with dark wing-tip and spot markings affected by sex and wear.
- Typical context
- Cabbage, broccoli, kale, cauliflower, and other mustard-family plants.
- Identification limit
- One organism, symptom, or photograph is not enough for reliable species certainty.
Key characteristics
- Velvety green caterpillar with faint pale lines; details change with growth.
- The adult is a white butterfly with dark wing-tip and spot markings affected by sex and wear.
- Host and habitat context matter: Cabbage, broccoli, kale, cauliflower, and other mustard-family plants.
- Color, size, and plant injury can overlap with unrelated organisms; preserve uncertainty when views are incomplete.
Life stages
01
Larva
Velvety green feeding stage on brassicas.
02
Adult
White butterfly stage laying eggs on suitable hosts.
Where it is found
- Cabbage, broccoli, kale, cauliflower, and other mustard-family plants.
- Larvae feed openly on leaves and may leave green-brown frass near chewing.
- Regional range and seasonal timing affect which species are plausible.
Behavior and activity
- Larvae feed openly on leaves and may leave green-brown frass near chewing.
- Visible abundance can change with weather, plant condition, natural enemies, and life stage.
- Plant damage without the organism present does not establish the cause.
Diet and resources
- Plant or habitat relationship: Cabbage, broccoli, kale, cauliflower, and other mustard-family plants.
- Resource use varies within broad groups and should not be generalized beyond this entity scope.
Associated signs
Irregular holes and leaf loss on brassicas support caterpillar feeding but are not species-specific. These signs also have other pest and non-pest explanations.
Common lookalikes
Green caterpillars moving with a looping gait.
Smaller tapered brassica feeders that may drop on silk.
Adults require wing-pattern and regional comparison.
Why it matters
Identity and impact are separate questions
Feeding can reduce usable foliage or damage young brassicas, but plant stage and abundance determine significance.
- Do not infer the responsible species from damage alone.
- Assess current activity, affected area, plant health, and change over time before deciding whether action is warranted.
Management direction
- Compare movement, texture, prolegs, and host.
- Inspect leaf undersides and protected centers.
- Use brassica-specific IPM if feeding exceeds acceptable levels.
Have a pest photo to check?
Start a new photo identification. This Profile gives comparison context; it does not transfer certainty or diagnose your image.
Identify a photoReviewed guidance and sources
Last reviewed August 2026. Sources support the claims listed with them; their limits remain part of the review.
- University of Minnesota Extension — Caterpillar pests of cole crops
Supports: Morphology, brassica hosts, injury, and caterpillar comparison.
Does not support: Identity from holes alone.
Scope note: North American garden and landscape context; species, hosts, seasons, and local guidance vary.
- University of Minnesota Extension — Common insects in vegetable crops
Supports: Host crops, life-cycle context, damage patterns, scouting, and IPM context.
Does not support: Species certainty from damage alone or a universal pesticide program.
Scope note: North American garden and landscape context; species, hosts, seasons, and local guidance vary.