Spread by ‘cuckoo spit’

Xylella fastidiosa is spread by insects such as leafhoppers and froghoppers which leave ‘cuckoo spit’ – white frothy blobs on leaves

It could threaten British oaks, elms, cherries and lavender plants

The disease causes leaf edges to turn brown, which can be mistaken for frost or drought

Previously only seen in the US and Taiwan

Appeared in Europe in 2013, spreading to Corsica, south France, Spain and the Balearic islands

It hit a million trees in Italy, causing olive oil shortages last year