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Root maggots

Insect or pest Delia radicum, D. antiqua · also called cabbage maggot, onion maggot

Damaged roots or bulbsWilting or dying plants

How to spot it

Small white legless maggots, about 1/4 inch long, in roots and bulbs. The adults are gray flies that look like small houseflies.

What it does

They tunnel into radishes and turnips, the roots of cabbage-family plants, and onion bulbs. Plants wilt, yellow, and die, and roots rot.

What to do now

  • Pull and throw away infested plants, with the soil around the roots.

Keep it away next time

  • Cover beds with row cover right after sowing.
  • Grow these crops in a new spot each year.
  • Wait for warm soil, or sow a later crop to miss the spring flies.
  • Put a square of cardboard or tar paper around the stem of each cabbage transplant.

Helpful supplies

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Plants it affects

Not sure? Your county extension office can identify it from a photo or sample, often for free.