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Caterpillars on cole crops

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.
A tiny, oblong, yellow egg on a leaf
Imported cabbageworm egg
Green, fuzzy caterpillar with a light yellow stripe down its back crawling on a leaf
Imported cabbageworm larva
Light gray moth with a white furry body and long antenna feeding on the center of a flower
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.

Yellow-colored, tiny, pin-point eggs on the underside of a leaf
Cabbage looper eggs
Shiny green caterpillar with slender hairs poking out randomly crawling on a leaf and eating a cucumber slice
Cabbage looper larva
Grayish brown moth with four legs
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.
Thin, green caterpillar chewing a hole in a cabbage leaf
Diamondback moth larva
A slender, light-brown moth on a green leaf
Diamondback moth adult
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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.

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

Reviewed in 2019

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