The new flies lay more eggs which change to maggots. This group causes plant damage into the fall. Some flies may develop in the fall. These insects spend the winter as puparia in the soil or as maggots in the roots. Maggots from the August-September generation cause the greatest damage.
Damage generally increases the longer the carrots are left in the ground.
Carrot rust fly damage. Carrot rust fly adult. Carrot rust fly larva. There are no registered chemicals which can be used for control of carrot rust fly on other plants. Where rust flies are serious pests, place carrots and other infested plants that are badly damaged in the garbage can quickly.