, Farm Journal Seeds & Production Editor
My mother strictly forbid the use of four letter words. It's not what you think—one of the top on the forbidden list was the word "hate.” As children we were never allowed to "hate” anyone or anything. But here's a confession. The farm kid in me despised black cutworms.
I distinctly remember more than one incidence when my father and I stood together to admire a field of perfectly emerged corn. Only days later, we returned to find the same field callously mowed down by the dastardly devils. That was before the days of pheromone traps and records of moth flight. It was before traits like Agrisure Viptera.
Agrisure Viptera is a new corn trait from Syngenta designed to control a variety of lepidopteran pests. Beyond the hated (sorry Mom) black cutworm, there's other voracious worms like corn earworm, Western bean cutworm and fall armyworm. Bruce Battles, Syngenta Seeds agronomy marketing manager, refers to them as the "multi-pest complex.”
The bad news is Battles is seeing the perfect storm for black cutworm pressure this spring. "In some areas of the Midwest [like Missouri], we are seeing fairly early signs of clipping,” says Battles. "Iowa, Minnesota, South Dakota, Nebraska and Wisconsin have been pretty quiet so far, but we've observed lots of moth flight in those areas and the potential for egg laying has been high.
"The black cutworm larvae that have emerged are hanging out feeding on weeds and waiting,” Battles adds. "We're concerned because the cool temperatures and late planting could result in corn emerging when larvae are fairly large. They do the most damage to corn when they are about 3/4-inch or around the 4th instar.”
Agrisure Viptera is awaiting registration, but anticipated to be available for 2010 planting. Battles says the company has been evaluating the trait's effectiveness against black cutworm in replicated field trials for the past four years. Because black cutworm can be sporadic, fields were actually inoculated with the pest to look at worst case scenarios. Healthy larvae in the 1/2 –inch to 3/4 –inch stage were introduced onto corn plants at the rate of 1.5 larva per plant.
"That's heavy pressue,” Battles says. "But we really wanted to put the trait to the test. From 2005-2008 over 19 locations, we found roughly 3% cutting in Agrisure hybrids stacked with the Viptera trait compared to 34% cutting in Agrisure hybrids containing CB/LL/RW traits.”
Battles notes that black cutworm is only the first of the caterpillar feeders. He believes farmers will find Agrisure Viptera to be particularly effective on corn earworm. "That's an insect that causes a lot more damage than most people think. It doesn't have a distinct flight pattern and farmers need a product that will control it over a long period of time,” he says.
"We are encouraging farmers to consider these pests as a package, rather than as an individual threshold,” Battles adds. "We believe this multi-pest complex is causing enough damage that growers should consider protecting themselves throughout the season.”