Question to the Department for Environment, Food and Rural Affairs:

To ask the Secretary of State for Environment, Food and Rural Affairs, how many incidences of each notifiable tree disease have been reported to his Department; what species of tree was affected by each disease; and when the notifications were made.

The Tree Health Diagnostic and Advisory Service (THDAS) at Forest Research provides advice and where possible diagnosis and identification of tree pests and pathogens. The Forestry Commission has developed TreeAlert, an online tool to help gather information about the health of the nation's trees, woodlands and forests, which allows individuals to report any suspected tree pests and diseases. Over half of the enquiries received at THDAS come through TreeAlert. The rest of the enquiries come via email, letter, telephone or visitors.

From 2015 to 30 September 2018, THDAS identified 1820 cases of notifiable trees pests and diseases. Of these, ash dieback and oak processionary moth were the most frequently reported notifiable pests and diseases. The reports received included a range of different tree species affected by pests and diseases.