Weevil released to control invasive thistle ended up harming 25 native species

The US launched a biological control program to manage musk thistle, an invasive plant, by releasing a targeted weevil species. However, the insect spread beyond its intended target and began attacking native thistle species as well. Among those affected was an endangered variety, which suffered a notable decline in seed production. The unintended consequences highlight significant risks in biological pest control strategies. Experts say the incident underscores the need for thorough ecological assessment before introducing any biocontrol agent.