How to Manage Pests

Pests in Gardens and Landscapes

Carrot rust fly—Psila rosae

The larval forms of the rust fly are stiff white maggots about 0.33 inch long. Adults are small flies.


Carrot rust fly larvae cause surface tunnels in roots. Tunnels are filled with a rusty mush and the stiff white maggots. There are no aboveground symptoms.


Plant carrots to avoid the egg-laying periods of the fly. In cold areas, plant in early summer. In more mild areas, plant in late winter or late summer. Covering seedbeds with row cover or individual plants with protective cones may help prevent infestations. Harvest carrots as soon as possible and in blocks rather than selectively. Before using carrots, peel off damaged areas. Do not store carrots in ground through winter. Carrot rust fly also attacks parsley, celery, and other related plants. Remove these sources of infestation also.

Carrot rust fly adult
Carrot rust fly adult

Tunnels in taproots caused by larvae
Tunnels in taproots caused by larvae

Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2017 The Regents of the University of California. All rights reserved.

For noncommercial purposes only, any Web site may link directly to this page. FOR ALL OTHER USES or more information, read Legal Notices. Unfortunately, we cannot provide individual solutions to specific pest problems. See our Home page, or in the U.S., contact your local Cooperative Extension office for assistance.

Agriculture and Natural Resources, University of California

Accessibility   Contact webmaster.