About AzollaControl

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.