First report of Sirococcus tsugae in the United Kingdom
In the United Kingdom, a sample collected from a symptomatic Cedrus atlantica tree (Atlantic cedar) grown at a private residence was sent in autumn 2013 to Forest Research for diagnosis. In February 2014, the pathogen was identified as Sirococcus tsugae (EPPO Alert List) using molecular tests. This is the first time that S. tsugae is reported from the UK. It is noted that during the last few years, severe shoot blight and defoliation of Cedrus atlantica had been observed. However, as there are similarities between S. tsugae and S. conigenus (which is known to occur in the UK), S. tsugae may have been present for some time and classified as S. conigenus. Following this initial finding, S. tsugae has been detected in 21 other locations in England, Wales and Scotland. In addition to C. atlantica, S. tsugae has been identified in an herbarium specimen of Tsuga mertensiana collected in Scotland in 2004 and in young T. heterophylla regeneration in Southwestern England. In addition to symptoms of shoot blight and defoliation, shoot cankers and occasionally resin bleeding from the bark have also been seen in association with S. tsugae in the UK. These symptoms have not been reported in North America (where the disease occurs) and can lead to crown death when branches are killed by girdling cankers.
The pest status of Sirococcus tsugae in the United Kingdom is officially declared as: Present, limited distribution.
Note: In the EPPO region, S. tsugae has also been reported from Germany (see EPPO RS 2015/076), where it was detected in 2014 on two C. atlantica trees which were subsequently destroyed.
Sources
NPPO of the United Kingdom (2015-10).
INTERNET
Pérez-Sierra A, Gorton C, Lewis A, Kalantarzadeh M, Sancisi-Frey S, Brown A (2015) First report of shoot blight caused by Sirococcus tsugae on Atlantic cedar (Cedrus atlantica) in Britain. Plant Disease (in press).