The US will release non-native insects to control a hated and invasive species of thistle.
The weevil is to be used to fight the spread of the yellow starthistle, which first arrived in California before 1860.
The plant has quickly spread across most of the country’s states, although it is most prevalent in the west.
Its seeds can be carried by the wind, but also by vehicle tyres and even hiking boots.
Yellow starthistles are found in most US states. Pic: Franco Folini/Wikimedia Commons
Experts say that the weevil, native to Europe and western Asia, will be more effective in stopping the thistle’s spread than pesticides and physical removal.
The insects feed on the plant’s upper root for about two months before going inside the plant for their pupa stage.
When they emerge as adults they eat the thistle’s leaves.
The weevils are to be released in California in the spring, followed by Idaho, Oregon, Washington and possibly Nevada.
The US Department of Agriculture said the yellow starthistle’s long spines deter feeding and injure grazing animals.
Jeremey Varley of the Idaho State Department of Agriculture also said yellow starthistle is “not good to eat” and is toxic to horses.
“We’re really excited about the release of this weevil,” he added.
The agency has insisted there is little to no risk of the weevils attacking native plants.