Cabbage Root Maggots are found in most canola fields in the County. Populations are generally low and rarely occur in yield-reducing numbers. 


What is are the Risks?

The adult phase of the cycle is a fly which lays eggs in the spring. These eggs hatch as maggots which migrate to the root system of canola plants and begin feeding. The resulting severity of damage is related to the amount of maggots present. There is always a chance of yield loss due to an abundance of adults present and the amount of eggs laid.

What to Look For

   Cabbage Root Maggot Pupae      Cabbage Root Maggot Maggot     Cabbage Root Maggot fly

               Pupae                                                 Maggot                                             Fly                       

  Cabbage Root Maggot life cycle          Cabbage Root Maggot damage


There are no control measures for Cabbage Root Maggot available due to the nature of their cycle. Adult flies lay eggs over a lengthy period thereby making insecticide application unfeasible. There are, however, some cultural practices which you can do to help to reduce the impact of damage:

  • Plant canola crops using seed with high germination and vigour
  • Increase seeding rate if a problem is suspected
  • Widen row spacing
  • Assure good fertility with proper balance of nutrients for canola production

Related Links

Root Maggots in Prairie Canola Crops

Reduced-Risk Strategy for Cabbage Maggot Management in Brassica Crops