The water fern Azolla filiculoides Lam. (Azollaceae): from well-established to disappeared (H9)

A well-established and dense carpet of Azolla filiculoides was found within an unused cut and harbour in Co. Clare, Lough Derg. It was abundant in 2012 till 2014 and was no longer present in 2016. Using satellite imagery, the occurrence of the population would appear to have been there from 2009, or before, to 2014/2015. It is suspected that the weevil Stenopelmus rufinasus, which feeds on this fern, was responsible for its complete disappearance.