Entomologists report high southwestern corn borer moth numbers have been seen in corn throughout TN. Not all fields have reached threshold, but entomologist Dr. Scott Stewart suggests setting pheromone moth traps to check treatment levels in his July 11^th Pest Patrol update.

According to Oklahoma State University, the southwestern corn borer can reduce yields of corn and sorghum by 15 to 50%.

Traditionally, there are one to three generations each year, with the first generation appearing in early June and the second and third generations appearing in mid-to-late July. While moths are dull white, larvae initially have a pink or reddish color. As the larvae grow, they eventually develop black spots and the same dull white color seen on the moths.

Infested plants often have broken, frayed and drooping leaves, with noticeable holes from larvae feeding, and twisted stalks. Along with stunted plant growth, the southwestern corn borer’s feeding can also leave the plant susceptible to secondary diseases and weather damage.

Growers should proactively scout for pests during the growing season to prevent serious damage and infestations. If moths are detected, the University of Missouri suggests scouting on a weekly basis to prevent further damage.

If the state-determined economic threshold is reached and an application is needed, we recommend Force® CS or Force® 3G insecticide to preserve corn yield, or Warrior II with Zeon Technology® insecticide, which delivers the combination of consistently reliable performance, modern formulation technology and long residual insect protection.

For more pest alerts from entomologist Dr. Scott Stewart, check out his Pest Patrol page.

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