First report of Phytophthora pluvialis in the United Kingdom
The NPPO of the United Kingdom recently informed the EPPO Secretariat of the first record of Phytophthora pluvialis on its territory. P. pluvialis was discovered during routine surveys in a woodland in Cornwall in September 2021, where it was found to be affecting mature western hemlock (Tsuga heterophylla) and Douglas-fir (Pseudotsuga menziesii) trees. This is the first record of T. heterophylla as a host of P. pluvialis. P. pluvialis was described as a new species in 2012 in mixed tanoak-Douglas fir forests (Notholithocarpus densiflorus - Pseudotsuga menziesii) in the USA (Oregon) (EPPO RS 2015/169) and was reported to be the cause of red needle cast on Pinus radiata in New Zealand in 2014 (RS 2016/215).
A risk assessment has been done by the UK Plant Health Risk Group, which has concluded that Phytophthora pluvialis meets the criteria to be classified as a GB quarantine pest for regulatory purposes. Official measures are being taken and include the prohibition of movement of any wood, isolated bark and trees (including live trees, felled or fallen trees, fruit, seeds, leaves or foliage) of the genera Tsuga, Pseudotsuga, Pinus and Notholithocarpus, that originated within the demarcated area.
The pest status of Phytophthora pluvialis in the United Kingdom is officially declared as: Present, under eradication.
Sources
NPPO of the United Kingdom (2021-10).
Forestry Commission (2021-10-21) Guidance on Phytophthora pluvialis https://www.gov.uk/guidance/phytophthora-pluvialis