British canals threatened by ferns turn to weevil power

[Hobjob]

British canals threatened by ferns turn to weevil power

By Peter Woodman From the Indie

Invasive water ferns which threaten wildlife on Britain's canals are to be targeted with weevils.

British Waterways is to release the 2mm-long creatures into the Bridgwater & Taunton Canal in Somerset to eat the plant, which are voracious growers, multiplying rapidly, covering the water surface with thick mats and killing wildlife. Weevils are very effective in destroying the plant without damaging other species. Last year, British Waterways spent more than £400,000 destroying the plants.

________________________________________

I presume this relate to giant salvinia or kariba weed
Salvinia molesta - Wikipedia, the free encyclopedia

I remember seeing this in 74 in Lake Kariba, but I understood it went away when the nutrient levels of the water dropped?

Introducing biological control always seem fraught with potential dangers.

Does anyone know the reserach basis for this in UK?

[Lancashire Lad]

Hi Hobjob,

Could this be in relation to Azolla filiculoides water fern?

CABI has an ongoing programme for breeding and supplying the American weevil Stenopelmus rufinasus.

(See the "Results" page, - tabbed when viewing this link): -
CABI | Development and Research | Azolla control

There is also info on the background/development of this type of control.

Regards,
Mike.

[Hobjob]

Ah! Thank you Mike; I was way off target but you would have thought the journos would have given the name!

Excellent link.

Originally Posted by Lancashire Lad

Hi Hobjob,

Could this be in relation to Azolla filiculoides water fern?

CABI has an ongoing programme for breeding and supplying the American weevil Stenopelmus rufinasus.

(See the "Results" page, - tabbed when viewing this link): -
CABI | Development and Research | Azolla control

There is also info on the background/development of this type of control.

Regards,
Mike.

[Dorts]

As far as I am aware Giant Salvinia - Salvinia molesta is very sensitive to frost and dies after a hard winter, (and probably many other of these invasive exotics), so surely after last winter there will be very little left, other than perhaps around the odd 'warm-water' outlet?

Giant salvinia is listed under Schedule 9 to the Wildlife and Countryside Act 1981 with respect to England, Wales and Scotland. As such, it is an offence to plant or otherwise allow this species to grow in the wild.