Oregon State University scientist Fritzi Grevstad of the Department of Botany and Plant Pathology in the College of Agricultural Sciences petitioned the USDA to use the insects and led the research that resulted in the approval.
The USDA affirmed Monday that a leaf-eating insect from Asia can be turned loose on knotweed, an invasive plant that's cost more than $30 million over the past 15 years to control in Washington.
The psyllid Aphalara itadori will be the first biological control used against Japanese knotweed, as well as the related Bohemian and giant knotweeds.