Western bean cutworm (WBCW) has been on the move again, infesting cornfields in new territories. Growers in Illinois, Indiana, Iowa, Michigan, and Wisconsin have experienced the devastation of WBCW for the past several years, and some areas in Ohio saw egg masses and larvae in fields for the first time this season. Entomologists predict pressure from the insect could only increase in the coming years in eastern Corn Belt states.
"If WBCW follows the same trend it has in other states like Michigan and Indiana, growers in Ohio can expect to see economic damage from the insect in the next couple of years," says Andrew Michel, entomology professor at The Ohio State University. "Usually you’ll see scattered damage before economic damage."
WBCW larvae feed on pollen during tasseling, on the silks during silking and then finally on the developing kernels. Because the feeding occurs on the ears, the damage directly impacts yield. In a heavily infested field, WBCW can decrease yield by 30 percent to 40 percent. The presence of feeding burrows also makes the ear more prone to fungal and mycotoxin infection.
"WBCW can cause severe economic loss in corn. In-plant protection is critical for protecting yields because the larvae are difficult to control with a traditional insecticide application," says Bill Hendrix, Dow AgroSciences North America biology team leader for insect management traits.
Michel recommends growers become educated about WBCW — understanding its life cycle, tracking its migration, and learning how to scout for the insect — before it becomes a major threat in their area. He notes there are many resources on The Ohio State University Web site.
Other WBCW sources also are available on the following sites: