Cabbage Looper
Trichoplusia ni
0 host plants
Last updated
Data Maturity Baseline
This profile contains verified pest data from extension databases. Regional field notes and expert review are in progress.
Quick Reference
Order
Lepidoptera
Type
larva (leaf-feeding caterpillar)
Host Plants
0
Peak Activity
May through September; overlapping generations
Damage Severity
moderate
Monitoring & Action
How to Monitor
Check undersides of brassica leaves for eggs and small caterpillars. Look for the distinctive looping movement to distinguish from imported cabbageworm. Frass pellets on leaves indicate active feeding.
When to Act
Treat when caterpillars are present on young plants. Established plants tolerate moderate feeding.
What Damage Looks Like
Caterpillars chew ragged, irregular holes through leaves. Larger larvae can consume entire leaves leaving only veins and midribs. Leave dark green frass pellets on and between leaves. Can contaminate broccoli and cauliflower heads with frass.
Cultural Controls
- Floating row covers exclude adult moths from laying eggs on crops
- Hand-pick caterpillars; the looping motion makes them easy to identify on the plant
- Clean up plant debris at end of season to reduce overwintering pupae