A University of Nebraska–Lincoln entomologist has received nearly $430,000 for research that could lead to a better understanding of sorghum’s natural defenses against fall armyworm.
Joe Louis, associate professor in the university’s departments of entomology and biochemistry, received the funding through a three-year grant from the U.S. Department of Agriculture’s Agriculture and Food Research Initiative competitive grants program.
Sorghum is one of the world’s most important crops and is grown for both grain and bioenergy. Fall armyworm — the larval stage of the fall armyworm moth — is one of the most devastating pests affecting grasses in the Americas, Louis said. Recently, it has become an invasive pest in Africa, as well.
Fall armyworm feeds on plants belonging to more than 75 plant families, including sorghum, and infestations at critical stages of sorghum development can reduce grain yields by 55% to 80%. In addition, the continued reliance on insecticides and transgenic crops has led to the loss of insect resistance in field-grown crops. In sorghum, the extent of genetic variation and defense responses against fall armyworm are largely unknown, Louis said. His research will look at the natural variation in different lines of sorghum, which could shed light on the underlying mechanisms of sorghum resistance or susceptibility to fall armyworm.
At the same time, Louis and his team will look at how the pests overcome plants’ natural defenses. Salivary components — for example, salivary proteins — found in fall armyworm saliva can actually reprogram host plant cells and how they behave, he said.
“In addition to the plant defenses, we will also monitor how insects utilize counter-defenses to overcome the innate plant defenses,” Louis said. “Thus, this project will also extend the known repertoire of herbivore elicitors in overcoming plant defenses.”
Louis will serve as the project director and will work with Richard Boyles, a sorghum breeder and geneticist at Clemson University. Boyles will help with mapping the genetic variants in sorghum that are associated with resistance to fall armyworm.
Ultimately, Louis hopes the research unlocks the mystery of sorghum’s natural defenses against fall armyworm, as well as how the fall armyworm overcomes them. Eventually, Louis’ work could be used to develop armyworm-resistant varieties of sorghum or other environmentally friendly strategies of pest control.
“I’m very grateful to USDA/AFRI for supporting this multidisciplinary work,” Louis said. “This work is quite timely given the serious outbreaks of fall armyworm in various parts of the world.”