Froghoppers and Xylella
Xylella fastidiosa is a bacterial disease of a wide range of plants and causes symptoms including leaf scorch, wilt, dieback and plant death. It is causing serious problems in Southern Europe but it has not yet been detected in Britain. The disease is spread by insects that feed on the xylem of plants. This includes froghoppers.
Xylella is not in the UK but could be introduced through the importation of infected plants. The RHS is a partner in a collaborative project which aims to understand and prevent the introduction of vector-borne plant pathogens, especially Xyllela, to the UK and the challenges they pose to the UK flora. The BRIGIT project has been funded by the Biotechnology and Biological Sciences Research Council, Department for Environment, Food and Rural Affairs, and the Scottish Government to reduce this risk and to increase our capability to respond to an outbreak. The project is being undertaken by scientists in ten UK research organisations led by the John Innes Centre.
Spittlebugs are not a pest, so please don't remove them; they are an innocent carrier of Xylella outside of the UK.