Cabbage Root Maggot

What it looks like

Cabbage root maggots are the larvae of the cabbage root fly, which looks like a common house fly but smaller. The maggots are small and yellowish white, with a pointed head and a blunt back end.

The maggots do best in cool weather, which is why they mostly damage cool-weather crops like cabbage, broccoli, Brussels sprouts, and rutabaga.

The cabbage root fly goes through four life stages, with several generations per year. Adults lay eggs in the soil in spring and summer, and the eggs hatch after a few days. The maggots feed on roots for several weeks, then change into pupae in the roots or the soil. New adults usually come out a few weeks later, or the pupae spend the winter in the soil and come out the next spring or summer.

Damage

Cabbage root maggots feed on the roots of cabbage-family crops (also called cole crops) and other root vegetables, causing plants to wilt and sometimes die. Their tunnels through the roots also leave plants open to bacteria and other diseases.

How nematodes help

The beneficial nematodes in BioLogic's products hunt down and kill maggots in the soil. Killing the flies as maggots stops the life cycle, so new adults don't emerge.

How to apply

Treat with Scanmask from March to June. Apply it to transplants of cabbage-family crops and root vegetables before you plant them.

For severe infestations, treat the rows again a couple of days after transplanting, as a drench or a topdressing, and water heavily afterward.

See How to apply for step-by-step directions, or use the calculator on the Scanmask Spray page to see how much you need.