Cabbage Worms

Brassica-feeding Lepidoptera complex

Cabbage Worms is treated as a plant-pest complex affecting cabbage, kale, collards, broccoli, cauliflower, mustard, and related Brassicaceae. Chewing ranges from small shot holes to skeletonization and contamination of heads or florets with larvae and frass.

Identification

This umbrella covers imported cabbageworm, cabbage looper, diamondback moth larva, and other brassica-feeding caterpillars. Body form, proleg number, movement, and feeding pattern separate the component pests. The relevant host or site is cabbage, kale, collards, broccoli, cauliflower, mustard, and related Brassicaceae. Turn leaves, inspect growing points and heads, and classify larvae before counting them. Record small versus large larvae because control success differs sharply by size.

Symptoms / Signs

Chewing ranges from small shot holes to skeletonization and contamination of heads or florets with larvae and frass. Fresh feeding carries live larvae or new frass; old scars persist.

Life Cycle / Process

Each component species has its own egg placement, larval behavior, pupation site, and seasonal pattern. Larvae cause the damage, except grasshoppers, whose nymphs and adults chew. Control works best before larvae enlarge, bore, or seal themselves in silk.

Prevention

Inspect incoming plants and propagation material for eggs, small larvae, webbing, mines, or frass. Maintain crop records that link host stage with first egg or larval detection. Priority inspection target: cabbage. Focus species or category: Cabbage Worms.

Management / Control

Use row covers before moth or butterfly entry, remove crop residue, conserve parasitoids, and choose Bt or another selective product only after identifying the active caterpillar group. Base action on active feeding, larval size, crop stage, and tolerance. Killing moths or butterflies after eggs are laid does not reverse existing injury. Recheck the same unit for fewer larvae and less new feeding.

Procedure Steps

1. Inspect the true feeding site and collect the smallest active larvae. 2. Record eggs, larval size, frass, feeding, and natural enemies consistently. 3. Apply Bt, virus, or a selective labeled insecticide while larvae are small and exposed. 4. Close the Cabbage Worms incident only after new injury stops.

Safety Notes

Protect food, seed, packaging, workers, and Myco-Patrons during inspection and treatment. Use tamper-resistant placements where baits or traps are necessary, and keep pesticides off food-contact surfaces. Structural or termite work may require a licensed Florida pest-control operator.