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Monitoring and Controlling Sugarbeet Root Maggot


This page was adapted from the article, "Sugarbeet Root Maggot Alert: Fly Activity to Hit High Levels in Next 2 to 5 Days," which appeared in Crop & Pest Report on June 16, 2022.

NDSU is partners with the American Crystal Sugar Company to monitor sugarbeet root maggot (SBRM) fly activity in growers’ sugarbeet fields in North Dakota and Minnesota. In 2022, the SBRM monitoring program is conducting fly counts in about 125 RRV sugarbeet fields throughout the entire RRV sugarbeet production area. 

The most severe outbreaks in 2022 were observed near the following communities:  Auburn, Buxton, Crystal, Drayton, Glasston, Grand Forks, Hensel, Oakwood, Reynolds, St. Thomas, and Thompson, ND, as well as Climax, Donaldson, East Grand Forks, Eldred, and Sabin, MN.  Other areas with moderately high fly counts include Ardoch, Bowesmont, Cashel, Cavalier, Hamilton, Hoople, Nash, and Voss, ND, and Ada, Angus, Argyle, Climax, Crookston, Helma, and Warren in Minnesota.  Fly counts from both NDSU and ACSC monitoring routes, are posted every Monday, Wednesday, and Friday evening on the School of Natural Resources Sugarbeet Entomology pageNOTE: this monitoring project is aimed at providing a general idea of where potential root maggot fly hot spots are developing throughout the growing season.  Sugarbeet growers and crop production advisors are encouraged to do their own monitoring in fields for which they may have concerns.


Growers choosing to use a granular postemergence insecticide should have already applied it by now; however, adequate control may still be achievable by applying granules immediately, or at least 3 days before peak fly if the application is made shortly before an expected rain.  Postemergence liquid insecticides work best if applied close to (i.e., 2-4 days before, during, or within 2 days after peak fly activity.  As such, growers expecting to use a liquid spray should monitor fields closely during the next week to 10 days for potential fly activity resurgences.  Growers in the southern RRV who need to apply a postemergence liquid spray should do so as soon as possible, and granular insecticides are probably not a viable option at this time.  Those in the central and northern RRV should plan to spray fields between Friday (June 17) and Sunday (June 19).  For more information, monitor local agricultural media sources (radio, The Crop & Pest Report, and the “Fly Counts” web page (address listed above) for further updates on root maggot control and other insect pest management topics.

Remember to always READ, UNDERSTAND, and FOLLOW all label directions and precautions.  It is illegal to use a pesticide in a manner inconsistent with its label.  For more guidance on postemergence control strategies, consult the “Insect Control” section of the Sugarbeet Production Guide.