Implementation of Biological Control Measure at Royal Military Canal

The Royal Military Canal is a designated ancient monument which is widely known for its rich biodiversity.

This can sometimes be threatened by non-native invasive species, specifically, floating pennywort FPW (Hydrocotyle ranunculoides). FPW is a one of the most invasive aquatic weeds in the UK, having spread rapidly from garden ponds into the waterways.

CABI is a UK based international, intergovernmental, not-for-profit organisation. CABI specialise in the control of invasive species and identified the weevil, Listronotus elongatus, as a FPW predator. DEFRA funded research began in 2011 and after a decade of safety testing and research, a South American weevil was approved for release in England to act as a natural pest control. The weevil was subsequently given ministerial approval for release in 2021 and a coordinated release strategy began during the summer of 2022 to trial the weevil at selected sites in England to try to establish populations.

CABI is the sole distributor of this type of FPW biological control in the U.K. CABI have released on 13 sites since the approval and have 7 more sites planned for this year. The Environment Agency are very supportive of this project and are keen to monitor its progress over the next two years.