Corn: Corn Rootworm (Diabrotica virgifera and Diabrotica barberi)


Pub 812: Field Crop Protection Guide > Chapter 1: Corn > Corn Rootworm


Field Crop Protection Guide 2011-2012, Order 2011-2012 publication

Table of Contents

  1. Description
  2. Integrated Pest Management Options
    • Soil-Applied at Planting Only
      • tefluthrin - Force 3 G
      • chlorpyrifos - Lorsban 15 G, Pyrifos 15 G
    • Seed Treatment
      • clothianidin - Poncho 1250
      • thiamethoxam - Cruiser 5 FS
    • Transgenic
      • Bt corn - Agrisure 3000GT, Agrisure RW, Agrisure Viptera 3111, Genuity
        SmartStax, Genuity VT Triple Pro. Herculex RW, Herculex XTRA, SmartStax, YieldGard Plus, YieldGard VT, Rootworm, YieldGard VT Triple
  3. Related links...

Description

There are two species of corn rootworm in Ontario. Western corn rootworm (WCR) adults are yellow to green with three, wavy black stripes on their wings. Northern corn rootworm (NCR) adults are uniformly green to yellowish. Larvae are white with a brown head and a distinct dark tail plate; they are approximately 1 cm in length.

Image 1. Western corn rootworm adults are yellow to green with three wavy black stripes on their back.
Image 1. Western corn rootworm adults are yellow to green with three wavy black stripes on their back.

Image 2. Northern corn rootworm adults are usually green to yellow and have no stripes.
Image 2. Northern corn rootworm adults are usually green to yellow and have no stripes.


Integrated Pest Management Options

Soil-Applied at Planting Only

Avoid planting corn following corn. Crop rotation is the best strategy for control. Risk factors include heavier soil (clay), high beetle populations in corn of previous season, and being the latest field planted in the previous season.

If there is less than 1 beetle per corn plant on average throughout the month of August, then no insecticide is necessary in the following corn crop.

In-furrow application is safer to the applicator and non-target animals than T-band application.

 
Active ingredient tefluthrin
Trade name Force 3 G
Rate (product) 37.5 g per 100 m (328 ft) row
Comments May be applied in a T-band or in-furrow. For banded applications, place directly over the furrow in a 15-cm band ahead of the press wheel. For in-furrow applications, place all material directly in the open seed furrow, behind the planter disc openers.

 

 
  Lorsban 15 G Pyrifos 15 G
Active ingredient chlorpyrifos chlorpyrifos
Trade name Lorsban 15 G Pyrifos 15 G
Rate (product) 75 g per 100 m (328 ft) row 75 g per 100 m (328 ft) row
Comments Must be applied in a 10–15-cm band over the row behind the planter shoe, in front of the press wheel. Do not place in direct contact with seed. 24-hr re-entry period.

 


Seed Treatment

Seed treatments are best suited for those fields at high risk of rootworm infestations, especially if planting corn after corn.

 
Active ingredient clothianidin
Trade name Poncho 1250
Rate (product) 166.7 mL per 80,000 kernels
Comments For use in commercial seed treatment facilities only. For low-to-moderate rootworm populations. Seed-applied insecticides can affect seed drop and final plant stands. Use talc or graphite according to planter recommendations to ensure planting accuracy. A 30-day plantback interval for cereal grains, grasses, soybeans and dried beans is required.

 

 
Active ingredient thiamethoxam
Trade name Cruiser 5 FS
Rate (product) 166.7 mL per 80,000 kernels
Comments For use in commercial seed treatment facilities only. For low-to-moderate rootworm populations. Do not graze or feed livestock on treated areas for 45 days after planting.

 


Transgenic

There are some potential causes of western corn rootworm developing resistance to Cry3Bb in the U.S. Using Bt corn product with multiple Bt traits that control corn rootworm may help to slow resistance development. To manage potential rootworm resistance, plant the appropriate refuge for the Bt corn trait used and follow all insects resistance management strategies mandated by the Canadian Food Inspection Agency. Refuge can be treated for rootworm larvae with soil-applied insecticides if thresholds perscribe it.
For more information regarding Bt corn and/or refuge options, see the Canadian Corn Pest Coalition website at www.cornpest.ca. See Table 9-4.

 
Active ingredient Bt corn
Trade name Agrisure 3000GT, Agrisure RW, Agrisure Viptera 3111, Genuity SmartStax, Genuity VT Triple Pro. Herculex RW, Herculex XTRA, SmartStax, YieldGard Plus, YieldGard VT, Rootworm, YieldGard VT Triple
Rate (product) See Table 9-4, Transgenic Crops Expressing Insecticidal or Fungicidal Traits, on page 119, for Bt corn options.
Comments Use Bt hybrids in fields of continuous corn with moderate-to-high populations of rootworm. Keep careful and accurate records as to where Bt and non-Bt hybrids are planted.

 


Related links...

 


For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca
Author: OMAFRA Staff
Creation Date: 2 May 2011
Last Reviewed: 10 May 2011