Phytophthora ramorum
Phytophthora ramorum, a pathogen causing disease in oaks on the west coast of America, was first discovered in Britain in April 2002. In October 2003, it was found in a southern red oak tree (Quercus falcata) growing in south-east England. There have since been a number of findings on several other oak species as well as ash, European beech, horse chestnut, sweet chestnut, and sycamore. View details. A summary of over 1000 sites was carried out to determine whether the disease is established in our woodland environment and subsequent surveys have been carried out in 2005 and 2006. To see copies of the reports
The Plant Health (Forestry)(Phytophthora ramorum)(Great Britain) Order 2004 (Statutory Instrument 2004 No 3213) which came into effect on 29th December 2004, imposes controls on imports of host trees, plants, wood and bark from the USA to prevent further introductions and prohibits the introduction into and spread of P. ramorum within Great Britain. To see Statutory Instrument 2004/3213.
We are investigating a recent outbreak of Phytophthora ramorum on Japanese Larch trees in Devon, Cornwall and Somerset. This is the first time that stem lesions caused by P. ramorum have been found on conifer species. Many of the infected trees are not growing in proximity to rhodendron (known to be a host of P. ramorum) which raises the question of how they have become infected. Symptoms have also been found on Western Hemlock and a selection of broadleaf species (beech, birch, and some oaks) growing in the same area.
- Phytophthora Ramorum
Dendroctonus micans (The Great Spruce Bark Beetle)
To view our information note (PHL9A) about the abandonment of the D micans protected zone w.e. from 15/5/05. - Phytophthora kernoviae
To view our guide on control techniques for Dendroctonus micans.
Note: with the abandonment of the protected zone for Dendroctonus micans (see PH9A, above), readers should ignore the section headed "Control Strategy" on pages 1 and 2, and paragraph (a) in the section "Outbreaks - options for practical control if presence of Dendroctonus micans is suspected" on page 8. It should also be noted that the Treatment of Spruce Bark Order mentioned on page 10 has been revoked.
