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Caterpillars on cole crops in home gardens

Quick facts

  • Cole crops include cabbage, cauliflower, broccoli, kale, rutabaga, radish, turnip and collard.
  • The most common caterpillar pests of cole crops are imported cabbageworm, cabbage looper and diamondback moth.
  • The imported cabbageworm is the most common caterpillar in gardens.
  • All caterpillars feed between the large veins and midribs of cole crops.
  • Older, larger caterpillars cause the most feeding damage.
  • Treat caterpillars when they are still small and before they cause too much feeding damage.

How to identify caterpillars

Imported cabbageworm (Pieris rapae):

Adult butterflies are commonly seen flying around plants during the day.

  • Adults are white butterflies with black spots on the forewings.
  • Eggs are yellow and oblong, and are on both upper and lower sides of leaves.
  • Caterpillars can grow up to 1 inch in length and are velvety green with faint yellow stripes running lengthwise down the back and sides.
  • They move sluggishly when prodded.
Imported cabbageworm egg
Imported cabbageworm larva
Imported cabbageworm moth

Cabbage looper (Trichoplusia ni):

Adults are nocturnal moths with a 1½-inch wing span.

  • Adult moths have mottled grayish brown wings.
  • A small silvery white figure 8 is in the middle of each of the front wings.
  • Eggs are creamy white, aspirin-shaped, and about the size of a pin head.
  • Adults lay eggs on the undersides of the lower leaves.
  • Caterpillars are pale green with narrow white lines running down each side.
  • Full grown caterpillars are about 1½ inches long.

Cabbage looper caterpillars have no legs in their middle sections and make a characteristic looping motion as they move across vegetation.

Cabbage looper eggs
Cabbage looper larva
Cabbage looper moth

Diamondback moths (Plutella xylostella):

Adult moths are nocturnal flyers.

  • Moths are light brown and slender.
  • The folded wings show a pattern of three white diamonds.
  • Eggs are laid near leaf veins on the leaf, and are creamy white and tiny.
  • Caterpillars are light green, tapered at both ends and grow up to 1/3 inch long, much smaller than imported cabbageworms and cabbage loopers.
  • They wiggle vigorously when touched.
Diamondback moth larva
Diamondback moth adult

How to protect your garden from caterpillars

Check for caterpillars and their feeding damage on both sides of leaves on cole crops. Check at least once a week right after planting and more often as the season progresses.


Jeffrey Hahn, Extension entomologist and Suzanne Wold-Burkness, College of Food, Agricultural and Natural Resource Sciences

Reviewed in 2019

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