Planning reference

Flea Beetles vs Cabbage Worms

Separate brassica shot-hole feeding from caterpillar chewing before spraying, re-sowing, uncovering rows, using Bt, or removing damaged seedlings.

Problem diagnostic

Flea Beetles vs Cabbage Worms cockpit

Start with shot holes, jumping adults, green caterpillars, underside eggs, frass, butterflies, seedling age, cover timing, and harvest access before choosing Bt, covers, or re-sowing.

Shot holes and caterpillar chewing need different brassica scouting before covers or Bt.
  1. 1 Flea beetle clues Small shot holes, shallow pits, jumping adults, weeds, and tender brassica seedlings.
  2. 2 Cabbage worm clues Green caterpillars, underside eggs, frass, white butterflies, and larger chewed edges.
  3. 3 Brassica proof Tap leaves, flip undersides, and check row-cover timing before Bt, covers, or re-sowing.
Brassica checks
Tap + fliptap leaves for beetles, flip undersides for worms
Seedling risk
Earlycotyledons and young brassicas need closer checks
Bt timing
Earlysmall exposed larvae are the Bt target

What each brassica signal means

Flea beetles
Flea beetles are tiny jumping leaf beetles that chew small shot holes in brassica leaves, hit direct-sown and newly transplanted seedlings hardest, and often build where weeds or plant debris shelter adults.
Cabbage worms
Cabbage worms are caterpillars on cabbage-family crops; imported cabbageworms, loopers, and related larvae chew larger ragged holes, leave frass, and often start after butterflies or moths lay eggs on leaves.
Shot-hole feeding and tiny jumping beetles
Many pinprick holes, tiny dark or striped beetles that hop when disturbed, and fast injury on young broccoli, cabbage, kale, turnips, or radishes point toward flea beetles.
Green caterpillars, frass, and white butterflies
Velvety green caterpillars, looping larvae, frass pellets, white butterflies, and eggs on leaf undersides point toward cabbage worms and loopers, especially when holes enlarge between leaf veins.
Row cover, Bt, and harvest timing
Row covers help when installed before pests arrive and kept sealed. Bt and handpicking target small caterpillars, not jumping flea beetles, and timing matters before brassica leaves or heads are harvested.

Brassica pest workflow

Check the feeding pattern first
Do not treat every chewed brassica leaf the same way; check for shot-hole feeding, tiny jumping beetles, white butterflies, green caterpillars, eggs on leaf undersides, frass, seedling age, row-cover timing, weeds, plant debris, and pollinator or harvest timing before spraying, uncovering, re-sowing, or removing plants.
Scout leaf undersides and crowns
Tap leaves and watch for jumping adults, then flip leaves to look for eggs and caterpillars before deciding whether the problem is beetles, worms, slugs, cutworms, aphids, or whiteflies.
Protect seedlings early
Use floating row covers immediately after planting high-risk brassicas, especially direct-sown or newly transplanted seedlings, and keep edges sealed so beetles or butterflies are excluded instead of trapped inside.
Match treatment to pest biology
Handpick or use Bt only for confirmed small caterpillars. Flea beetles need exclusion, weed cleanup, plant vigor, and debris reduction rather than caterpillar-specific controls.
Clean up between brassica plantings
Remove crop residue, manage weeds, and rotate brassica beds so overwintering adults and repeated caterpillar hosts do not stay concentrated around the next planting.

Use these paths

Source basis