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Yield and Quality Problems Caused by Western Bean Cutworm (WBC)

Western bean cutworm can cause serious quality issues in corn

Western bean cutworm (WBC) grabbed headlines in the fall of 2009. It’s a pest that’s new to Ontario and unfortunately it’s on the move. There were some pockets in Ontario where damage was quite extensive.

Although Western bean cutworm is native to North America, it did not materialize in Ontario until recently. That initial fall saw a scramble for information on this new pest and for crop protection tools to minimize its destruction of key crops in Ontario.

What is WBC?

  • A pest of field, sweet and seed corn and dry beans
  • It feeds on the corn ear and can cause a decrease in yield and quality
  • WBC overwinters in soil chambers
  • Young WBC larvae feed on tassels and silks and then tunnel into the ear 

Why are they just showing up now?

Several factors may be causing WBC to increase, including reduced use of foliar insecticides and increased no-till.

Scouting techniques

  • According to the Ontario Ministry of Agriculture, Food and Rural Affairs, stay on top of field scouting when the corn crop is in the pre-tassel to full-tassel stages
  • Scout 20 plants in five areas of the field from early July to the end of August
  • Look for egg masses and young larvae on the top three to four upper leaves
  • Egg masses are white when they are newly laid and turn purple when they are ready to hatch within one or two days
  • Egg hatch is when an insecticide treatment is most effective 

DuPont™ Coragen® insecticide

DuPont™ Coragen® is particularly potent against larvae as they hatch from the eggs, although it is effective at multiple stages of the life cycle providing excellent crop protection. Field, seed and sweet corn growers can now use DuPont™ Coragen® to help optimize yield and quality through reliable and consistent control of Western bean cutworm.

The rapid cessation of feeding, residual activity and excellent rainfastness associated with Coragen® work to deliver long-lasting plant protection. It has strong ovi-larvicidal activity but also provides excellent control at the ovicidal and larvicidal stages.

Coragen® comes from a completely new group of chemistry – Group 28, the diamides.  As a result, it is an excellent tool against insects that may be resistant to other classes of chemicals.  It provides effective control of major worm pests that infect sweet corn including European corn borer, corn earworm and WBC. It’s an important product that helps maximize yield and quality. It’s also classified as a Reduced Risk insecticide and has minimal impact on beneficials when used according to label directions.

The information provided on this website is for reference only. Always refer to the product labels for complete details and directions for use.