Since 1971, Oregon has used a flea beetle against tansy ragwort; 7 years later, the state said the biocontrol had cut infestations by 90%

Oregon's real weapon against a toxic weed has been a beetle smaller than a grain of rice. In 1971, the Oregon Department of Agriculture introduced a tiny flea beetle, Longitarsus jacobaeae, to control tansy ragwort, a poisonous plant that was costing ranchers around five million dollars a year in livestock losses, according to a 2022 factsheet. Seven years later, officials said the beetle had reduced ragwort levels by 90 percent. More than five decades on, the Oregon Department of Agriculture still lists the flea beetle as an active, ongoing part of its ragwort management program, not a one-time fix.

What is tansy ragwort, and why did it scare farmers