THE first outbreak of a killer disease of larch trees in Yorkshire has been found in Ryedale.

Confirmation of phytophthora ramorum (PR) infestation has been found during aerial surveillance by the Forestry Commission's tree health team at Yearsley Woods, Gilling.

The outbreak is revealed in a report to the North York Moors National Park's Primary Land User Group.

It states that suspicious trees were identified and subsequent site investigations and laboratory tests have confirmed the presence of the disease.

Crispin Thorn, area director for the Forestry Commission in Yorkshire and the North East, said: "The level of infection is currently low, with only six trees showing symptoms of the disease.

"In order to prevent the spread of the disease the symptomatic trees are being felled and it is expected that a further two hectares will be felled as part of precautionary wider control measures.

"The total woodland area is 543 hectares with larch covering approximately 168 hectares.

"As part of our response to identifying the disease we are looking to schedule a further follow up aerial survey of the woodlands in the area to ascertain any signs of further infection."

Mr Thorn said PR could kill larch very quickly.

He said: "Larch can produce exceptionally high numbers of spores from infected foliage, by which the disease can spread to other host plants."

Rhododendron also suffers from PR.

Mr Thorn said: "The disease had been found at Gilling as a result of a combination of surveillance, survey work and effective reporting.

"It is critical that the sector works together to limit the spreads of pathogens."