Delia radicum

Definition

A species of anthomyiid fly (Diptera: Anthomyiidae) whose larvae are serious root-feeding pests of cruciferous crops. The pale, legless maggots tunnel through the cortical tissue of roots and hypocotyls, causing stunting, wilting, and often death of seedlings; damage is most severe in cool, moist soils of spring and autumn plantings. The adult is a small, drab grey fly approximately 6–8 mm long, superficially resembling a reduced house fly. Management relies on crop rotation, resistant rootstocks, insecticide-treated seed, and physical barriers such as root collars.

Etymology

From Latin radicum, genitive plural of radix (root), referring to the larval habitat.

Example

In brassica seedling trials, Delia radicum infestation reduced marketable yield by 40% when maggot densities exceeded five per root system.

Synonyms

• Cabbage root fly
• cabbage maggot
• root maggot
• turnip fly

Related Terms

• Delia
• Anthomyiidae
• root herbivory
• maggot
• crucifer
• Integrated Pest Management
• crop rotation

Usage Notes

Older literature frequently uses Delia brassicae, now synonymized. Common names vary regionally: 'cabbage fly' and 'cabbage root fly' predominate in Europe; 'cabbage maggot' usually refers specifically to the larval stage. Not to be confused with the superficially similar Delia floralis (onion maggot) or Delia antiqua.