Seed and Seedcare resources

Insect resistance management

In Canada, the Canadian Food Inspection Agency (CFIA) requires implementation of an IRM plan for Bt technologies. These programs are mandatory, and have been developed in conjunction with industry and academic representatives, as well as other key stakeholders.

The best way for growers to preserve the benefits and insect protection of Bt technology is to incorporate Integrated Pest Management (IPM) strategies on their farm. These strategies play a key role in managing pest resistance. Successful management of resistance in turn benefits the grower through higher quality production. IPM strategies include planting refuge, crop and trait rotation, scouting, and use of chemical insecticides.

Syngenta is committed to following and supporting the refuge requirements set by the Canadian Food Inspection Agency. Therefore, all growers must sign a Syngenta Stewardship Agreement before ordering any Agrisure insect protected corn for the 2018/2019 sales season, and continue to support the best management practices to reduce the potential risk of developing resistance to either the European corn borer (ECB) or corn rootworm (CRW) traits.

• Lead to insect resistance
• Slow down the introduction of new corn technologies that provide additional insect protection
• Affect individual grower access to Agrisure traited products


Scout refuge plantings to determine the level of insect pressure in your field. Then scout the Agrisure insect-protected hybrids to note their effectiveness and look for signs of damage that may indicate resistance to either the Bt trait or the CRW trait. If concerns arise, please contact your local Syngenta Agronomic Sales Representative immediately for further field investigation.


While some pest damage can be expected on traited corn, above an established root injury threshold is considered unexpected. In these cases, it is imperative to contact your local Syngenta Agronomic Sales Representative in order to preserve trait durability. Syngenta will work with you to evaluate the case. If resistance is suspected, a management strategy will by developed to monitor the pest and the appropriate assays will be conducted to monitor resistance.


Bacillus thuringiensis (Bt) proteins are toxic to specific pests, such as the European corn borer (ECB or CB) and the corn rootworm (CRW or RW). As the number of acres exposed to these Bt products increases, so does the potential for target insect pests to develop a resistance to Bt traits. Therefore, in order to preserve this technology now and into the future an Insect Resistance Management (IRM) plan was developed.


The refuge maintains a population of insect pests susceptible to the Bt proteins produced in insect- protected Bt corn. These susceptible pests mate with any insect pests that are resistant to the Bt proteins. Susceptibility is then passed on to offspring, helping preserve the long-term effectiveness of insect-protected Bt corn products.

Types of Refuge

A common refuge is a field or area of corn that serves as a refuge for both above-ground pests (e.g., European corn borer) and below-ground pests (e.g., corn rootworm) at the same time. The refuge can be within the Bt field or immediately adjacent to it.

A single pest refuge is a field that serves solely as a refuge for above-ground pests (e.g., European corn borer) or below-ground pests (e.g., corn rootworm), but not both. The single pest refuge approach can be used for both single Bt corn products and stacked Bt corn products (also known as the Separate Refuge option).

It is important to recognize that different products may have different Insect Resistance Management (IRM) requirements. On-farm mixing of any seed is not an approved method. Syngenta is pleased to provide hybrids with E-Z Refuge for built-in compliance.

 Agrisure Viptera 3111

 Agrisure Artesian 3011A


20% (corn borer / corn root worm)


Adjacent to, or within Bt field

(4 row minimum)

• Single Bt trait to control rootworm with or without single Bt trait to control ECB and/or Bt trait to control Multi-Pest Complex™

• Appropriate size to ensure enough refuge mates available

• Refuge positioned to best suit rootworm behaviour (greater resistance risk)

Agrisure Viptera 3220 E-Z Refuge

Agrisure 3122 E-Z Refuge

Agrisure 3120 E-Z Refuge


E-Z Refuge


5% appropriate refuge material blended into the bag

• Dual Bt trait to control European corn borer (ECB) and/or Bt trait to control Multi-Pest Complex™

• Appropriate amount to ensure enough refuge mates available

• Additional convenience to ensure refuge is planted in all fields

Agrisure Viptera 3110

Agrisure 3010

20% (corn borer)

Adjacent to, within, or up to 400m from the  Bt field

Any of the above trait versions available in water-optimizing Agrisure Artesan® option would not change the refuge requirements.

The Canadian Corn Pest Coalition, in collaboration with the Ontario Corn Committee and the Canadian Seed Trade Association and industry have developed a web-based calculator to help growers plan how to meet the minimum refuge requirements for each Bt corn hybrid on their farm. The calculator can be accessed at .


Refuge can be planted as a block, strips within the field, perimeter around the field, adjacent or a separate block within a 1/4 mile of the field.

  • 1/4 mile option may only be used for ECB refuge
  • A neighbour’s field does NOT meet the refuge requirements

Remember when calculating a refuge, the calculation must be based on total corn acres.

Corn Refuge Requirements

Strip Refuge

4 Row Minimum – Strips, blocks, or perimeter refuges must be a minimum of 4 contiguous rows wide to provide ample space for bug mating.


Corn Borer Treatment – Non-Bt foliar insecticide treatments for corn borer control may be applied only if economic thresholds are reached for one or more pests. Economic thresholds will be determined using methods recommended by local or regional professionals (e.g., Extension Service agents, crop consultants).

Corn Rootworm Treatment – Insecticide treatments for control of corn rootworm larvae may be applied. If rootworm adults are present at time of foliar applications, then corn fields with the Agrisure trait must be treated in a similar manner. 

Refuge Management

Refuge should be planted with a hybrid that is agronomically similar to and managed similar to your corn with Agrisure traits.

If a rootworm refuge is planted in a field that is in a crop rotation system, the corn hybrids with Agrisure traits must also be planted in a field that is in a crop rotation system.

If the rootworm refuge is planted on continuous corn, the corn hybrids with Agrisure traits may be planted on either continuous or in a crop rotation system.

Be sure to see the corn rootworm and western bean cutworm pest page for additional best management practices.

Before opening a bag of seed, be sure to read and understand the stewardship requirements, including applicable refuge requirements when planting insect protected traits as set forth in the Syngenta stewardship/technology agreement that you sign. By opening and using a bag of seed, you are reaffirming your obligation to comply with those stewardship requirements.

To view recommended planting layouts, maps and configurations, please visit the CANADIAN CORN PEST COALITION at or contact us for a Grower’s Handbook: 1-800-756-7333.

There are several resources available to assist with insect resistance management in Canadian fields: