How could biological control help you?
Research has shown the tiny 2mm long North American weevil Stenopelmus rufinasus (right) to be one of Azolla's main natural enemies.
The weevil has already been used to control the weed very successfully in South Africa, where after extensive host range testing and climatic matching, it was released as a biocontrol agent.
Even the heaviest infestations were brought under control within a matter of months, without the need for chemicals or further control measures
The weevils can be targeted at very specific sites where the weed is considered a problem.
Why are weevils the best solution for Azolla biocontrol in the UK :
They can only feed on Azolla species, so won't harm other plants
All mobile stages can consume large quantities of the weed
CABI has developed techniques to overwinter and mass produce large numbers of weevils for release early in the season
The weevil is already present in parts of the UK (first recorded in 1921), most likely hitching a ride on Azolla plants imported by garden centres and aquarists.
CABI studies have shown that fairy fern infestations can be brought under complete control using only the weevil in a matter of weeks.
What is the CABI AzollaControl project doing?