The worst outbreak of armyworms in recent memory could cost Arkansas farmers millions of dollars in crop losses, but rice farmers just received a bit of good news. The federal Environmental Protection Agency on Wednesday (July 28) granted a crisis exemption enabling growers to use a needed insecticide.
Entomologists submitted documentation to obtain a Section 18 exemption last week to use Intrepid on rice. The crisis exemption allows the use of Intrepid beginning July 28. Intrepid is labeled for use on other crops, but not rice.
“The specific exemption is still under review at EPA, but application can be made under the crisis exemption,” said Gus Lorenz, extension entomologist for the University of Arkansas System Division of Agriculture.
The outbreak stretches from the Arkansas/Louisiana border to the Missouri bootheel. Lorenz has called this year’s armyworm situation the worst he’s seen in his career. In the days since the exemption process began, Lorenz said “it has probably cost growers several millions of dollars.”
The first generation of armyworms matured into moths in Texas and Louisiana and flew northward. Now that they’re in Arkansas, “We’re making our own generation, which is what makes it so dangerous,” Lorenz said.
There’s also a chance that, depending on the environment, “the population could collapse,” he said. “There are some natural controls out there. When you get a big buildup, a lot of things can happen. There are a lot of naturally occurring pathogens that can help control them.”
The state’s 1.24 million acre rice crop isn’t the only one in peril. Pastures, soybeans, grain, sorghum, and other crops could be impacted.
“Fall armyworm is a particularly voracious caterpillar,” said Jarrod Hardke, extension rice agronomist for the Division of Agriculture. “They tend to surprise us because adults lay very large egg masses, but the earliest instar larvae eat very little. It’s not until they get older and start to spread out that they consume most of the food in their life cycle. This is why we go from zero to treat seemingly overnight.”