Horseradish
Symptom Cause  
Huge, ragged holes in leaves; feeding area spotted green with excrement
Cabbage Loopers
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Eating small holes in outer leaves
Diamondback Moth Caterpillar
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Foliage discoloration, wilting, plant dies
Harlequin Bugs
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Shot holes in leaves, mostly on underside
Horseradish Flea Beetle
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Hugh, ragged holes in leaves; feeding area spotted black with excrement
Imported Cabbageworms
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Metallic blue-black, 1/10 inch long, the adults chew egg-laying holes in the roots. The larvae are stout, legless, white.
Imported Crucifer Weevils
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Large dark spots on leaves
Leaf Spot
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Leaves curled, surrounded by web
Webworms
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White, circular blisters on leaves.
White Rust
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