A University of Kentucky Martin-Gatton College of Agriculture, Food and Environment researcher is leading a new project that could help farmers fight some of agriculture's hardest-to-control insect pests with a method designed to hit the target and leave other insects alone.
S. Reddy Palli, a professor in the UK Department of Entomology, received $749,888 from the U.S. Department of Agriculture's National Institute of Food and Agriculture for a four-year project focused on improving RNA interference (RNAi) for managing lepidopteran pests, such as fall armyworm.
"RNAi is a process that can knock down key genes in a pest, shutting down functions the insect needs to survive," Palli said. "Researchers and companies have spent years studying it as a pest-control tool. This method has shown promise in some insects, especially beetles, but has not worked nearly as well in other insects like lepidopteran pests, the group that includes moths and butterflies."
That gap matters to agriculture.
"RNAi does not work very well in major agricultural pests," Palli said, noting that his lab has spent about a decade trying to learn why and improve the technology. "Previous work from my lab led to nanoformulations that showed some progress, but the new grant is meant to push the method farther, to the point of commercial use."
The new project will focus on fall armyworm, a destructive pest that feeds on corn and many other crops. Fall armyworm causes economic losses across many crops and is especially difficult to manage due to its voracious feeding on multiple plant species, year-round breeding, ability to migrate, and strong detoxification system. Palli's team has already achieved 50%-65% mortality in larvae using nanoformulations of double-stranded RNA. The new goal is to reach 100% mortality through improved gene targets and delivery methods.
"The stakes stretch well beyond Kentucky," Palli said. "Fall armyworm is native to the Americas, but they have spread across Africa and Asia, where they have become a serious concern for crop production. The insect has especially been tied to food security problems in places that rely heavily on corn."
For farmers, one of the biggest appeals of RNAi is precision.
Palli said the kind of product his lab is trying to develop could be sprayed onto corn and would be designed to affect fall armyworm but not beneficial insects such as honeybees and monarch butterflies. That kind of target-specific action sets RNAi apart from many broad-spectrum insecticides and is a major reason researchers continue to work to improve it. The project description also lists testing for non-target effects as one of its next steps.
Palli has been involved in RNAi research since the technology first began drawing attention as a pest management method. Palli said his lab published the first paper showing the method could work against the Colorado potato beetle. He also pointed to work on Japanese beetles and said RNAi-based products are already in use against beetle pests such as corn rootworm and Colorado potato beetle. He added that another product was approved last year for mites that affect honeybee health.
That track record gives the team a clearer picture of both the promise and the limits of RNAi.
"In beetles, the method already has a path to the field. In lepidopteran pests, that path has been much harder to build," Palli said. "This grant is meant to help change that, giving researchers room to refine the science, test the best delivery system in greenhouse and field settings to see whether the method can move closer to real-world use for current pests and those drawing concern elsewhere."
Learn more about Palli's lab and research.
This material is based upon work that is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award numbers 2019-67013-29351 and 2026-67040-45668 and Hatch Project under award number 2351177000. Any opinions, findings, conclusions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the Department of Agriculture.
Research reported in this publication was supported by the U.S. National Science Foundation under Award No. 1238087, 1338766, 1338775 and 1821936. The opinions, findings, and conclusions or recommendations expressed are those of the author(s) and do not necessarily reflect the views of the U.S. National Science Foundation.
