Weevils tackle invasive azolla water fern on River Till
Thousands of beetles have been released on a Lincolnshire river to get rid of invasive water fern that is killing the native wildlife.
A 2.5m (4km) long blanket of the fast growing weed has covered the River Till, near Saxilby.
It has formed a dense mat on the surface of the water, depriving other plants, fish and invertebrates of light and oxygen.
Stenopelmus rufinasus, commonly known as the azolla weevil, exclusively feeds off the plant without harming any native species, the Environment Agency said.