Pest Information
Common names: Cabbage root maggot
Scientific name:
Delia radicum
Diptera:Anthomyiidae
Synonyms: Cabbage maggot, cabbage fly, cabbage root fly
Host plants
Broccoli, Brussels sprouts, cabbage, cauliflower, radish, rutabagas, turnips, and other cool season plants
Distribution
Asia, Africa, Europe, North America, USA
Damage
The larva eats the lateral roots, then tunnels into the
taproot, and sometimes bores into the base of the stem. Attacked plants will wilt and the
leaves will turn bluish. The plants become stunted or eventually die.
Description
Eggs are white, ovate-shaped, and less than 1 mm in size. These are laid on the stems or in the soil near the base of the plants.
Maggots (larvae) are soft and white; about 3-8 mm long. They have a pair of prominent forked
tubercles below the hind
spiracles that separate them from other Delia species.
Pupae are found close to the roots or sometimes within the plant where the larvae last feed. These are brown and
hard and are ovate-shaped.
Adults are dark-gray flies slightly smaller than the common housefly. They can fly up to 2 km to find suitable hosts to lay their eggs upon (CABI, 2000).