Common names: Cabbage root maggot
Scientific name: Delia radicum
Synonyms: Cabbage maggot, cabbage fly, cabbage root fly
Broccoli, Brussels sprouts, cabbage, cauliflower, radish, rutabagas, turnips, and other cool season plants
Asia, Africa, Europe, North America, USA
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.
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).