ISSUE #415

ISSUE #415 Sugarbeet Root Maggot Control In 2002


Root Maggot populations have declined in all factory districts except Drayton. Population declines are probably due primarily to much wetter than normal conditions in many areas. Flooding or saturated conditions in previous year beet fields after the soil thaws out and before fly emergence is particularily detrimental to root maggot larvae or pupae.

Root Maggot Control Rated Good to Excellent in 2001

Over 70% of 2001 American Crystal Sugar Company acreage was treated for root maggots. Growers rated control good or excellent on 92% of all fields.

Table 1: Evaluation of Root Maggot Control In 2001

Root Maggot Control
Insecticide No. of Apple. ExcellentGoodFairPoor
% of responses
Counter 15G 226 56 36 4 4
Counter 20CR 12 42 50 8 0
Lorsban 15G 60 55 35 8 2
Lorsban 4E 22 41 50 9 0
Temik 15G 3 67 0 0 33
Malathion 3 67 0 0 33
Other 4 50 50 0 0
Total: 330 54 37 5 3

Survey by Dr. Dexter et al, NDSU/U of MN

Shareholders are encouraged to continue to use granular insecticides that have given very good control in the past where moderate or heavy root maggot populations are expected.

Strategies for Achieving Excellent SBRM Control In 2002

  • Calibrate insecticide applicators
  • Select the correct insecticide and use rate
  • Equip the planter with windshields
  • Apply a second insecticide in high SBRM population areas
  • Use band or spoon applications for best results

Cost Effective Control:

NDSU scientists are again recommending insecticide rates based on expected root maggot population levels in 2002. The 6-lb./acre application rate of Counter should also effectively control wireworm problems.

InsecticideRecommended Rates (product/ac)
For Expected Population Levels
Timing Options
Counter 15G RUP 5.9 lb. 10.0 lb. 11.9 lb. Planting-time or Post
Chlorfos 15G RUP 10.0 lb. 10.0 lb. 13.4 lb. Planting-time or Post
Lorsban 15G RUP 6.7 lb. 10.0 lb. 13.4 lb. Planting-time or Post
Temik 15G RUP 6.7 lb. 10.0 lb. 14.0 lb. Planting-time & Post

RUP – Restricted Use Pesticide

Relative Insecticide RateApproximate Savings ($/A)
Low Versus High $10
Low Versus Moderate $6.75
Moderate Versus High $3.50

The standard application rate (10 lb product/ac) of labeled soil insecticides is recommended in areas where moderate SBRM infestation levels are expected. This rate should be sufficient if adequate soil moisture prevails after planting. Growers in areas where SBRM populations are expected to be high (fig. 1.) or in fields adjacent to those where SBRM problems were evident during the preceding year should consider the high labeled rate of their preferred insecticide.


Fig. 1. Anticipated SBRM Population levels for the 2002 growing season in the Red River Valley

CAUTION - Mustang Root Maggot Control - CAUTION

Mustang is ONLY registered for root maggot suppression. Mustang is best suited to use in areas with light SBRM populations where granular insecticides have been previously used primarily for wireworm control. Your agriculturist and the Pest Alert area of in the agronomy section has actual fly count numbers for May and June 2001 and site specific maps of fly populations. Mustang can provide savings of $4 - $10/acre when used wisely.

Sugar Beet Root Maggot Map for 2001 Crop

New Insecticide Approved

Mustang is a new insecticide approved for the first time in 2002 for sugarbeets in Minnesota and North Dakota. It is registered for control of many insect pests of sugarbeets. Check 2002 Pocket Guide for usage rates.


Mustang has a 50-day PHI Consider your pre-harvest schedule if using Mustang after July 15.

Mustang and Starter Fertilizer

Mustang can be tank mixed with starter fertilizer. The tank mix must be placed directly with the seed in the furrow if maximum benefit of the P in the starter fertilizer is to be realized. Never tank mix with more than 3 gpa of 10-34-0. Adding 2 or 3 gallons of water to the tank mix improves application uniformity and should minimize stand loss.