Citizen science charts horse chestnut tree pest spread

A citizen science study, involving more than 3,500 people, has revealed the spread and establishment of the horse chestnut leaf-miner in the UK.

It also suggests that a native species of wasp that preys on the tiny insect will not be able to curb its impact.

Read the article on BBC: http://www.bbc.co.uk/news/science-environment-25878202

New biosecurity posters

Learn how to keep exotic pest invaders, such as P. ramorum, out of our forests, nurseries, and landscapes. Biosecurity posters now available from Food and Environment Research Agency (FERA), UK. at this link.

Ash Dieback in UK

This is not P. ramorum, but a new strain of an invasive fungal disease in the UK that is having a serious impact on a native tree species.

Ash dieback: Government faces possible legal action
A nursery forced to destroy 50,000 ash trees after a fungal disease was found is considering taking legal action against the government for failing to block imports sooner.

Read the article on BBC News

Fourth genetic lineage of Phytophthora ramorum pathogen identified

The increasing intensity of the P. ramorum outbreaks in the UK led researchers to analyze samples from the new findings further, which resulted in the discovery of a fourth genetically distinct lineage of the pathogen.
Announcing this at the Fifth Sudden Oak Death Symposium in California recently, Clive Brasier, an emeritus professor with the Forestry Commission's Forest Research agency, said he believed, based on genetic analysis, that the previously unknown European Type 2 (EU2) lineage had been recently introduced into south-west Scotland and Northern Ireland.

Read the full article here

Natural stem infection of Lawson cypress (Chamaecyparis lawsoniana) caused by Phytophthora ramorum

This is the first report of C. lawsoniana as a natural host of P. ramorum. In November 2010, P. ramorum was isolated from a 4 m long by 60 cm wide aerial phloem lesion on another mature C. lawsoniana in a park near Clydebank, Scotland. There was heavy resinosis at the top of the lesion. Adjacent rhododendrons were also infected with P. ramorum. Ten other large C. lawsoniana at the Clydebank site had dieback and aerial or collar lesions caused by the recently introduced Phytophthora species, P. lateralis (SA Green, CM Brasier and JF Webber, unpublished). Such an overlap between P. ramorum and P. lateralis on C. lawsoniana on the same site is likely to lead to direct physical contact between the two species. Since they are closely related phylogenetically and produce similar fruiting structures (e.g. Brasier et al., 2010), such novel contact could result in their hybridisation (Brasier, 2000). This possibility is under investigation.

Read the full article here.

Not even celebrities are exempt

Linda McCartney memorial wood is destroyed by disease

When hundreds of trees were planted in remembrance of Linda McCartney, it was hoped that they would grow to be a living and lasting memorial to the first wife of Sir Paul McCartney.

Now, however, all the larch trees in Linda’s Wood have had to be chopped down because of a deadly disease sweeping the country.

The trees were the victim of Phytophthora ramorum, or sudden oak death, which has jumped species and is infecting other trees including larch and the Douglas fir.

Read more here - The Telegraph

 

UK government launches tree biosecurity plan

The UK government has said that it will invest £7m to tackle tree diseases, amid fears that millions of trees could be lost unless urgent action is taken.

The Tree Health and Plant Biosecurity action plan was launched as scientists confirmed the arrival of a deadly disease in England among urban trees.

Phytophtora lateralis was recorded in Devon on a Lawson cypress, a popular species in parks and gardens.
Ministers hope the plan will tighten biosecurity measures and protect trees.

Read the entire article on BBC News.

Research article: Phytophthora ramorum in England and Wales: which environmental variables predict county disease incidence?

Chadfield, V. and Pautasso, M. 2011. Phytophthora ramorum in England and Wales: which environmental variables predict county disease incidence? Forest Pathology. DOI: 10.1111/j.1439-0329.2011.00735.x.

Abstract:  Phytophthora ramorum is the oomycete pathogen responsible for Sudden Oak Death on the West Coast of the USA and Sudden Larch Death in the British Isles. It also causes twig dieback and leaf blight on a series of ornamental hosts (e.g. Rhododendron, Viburnum, Pieris and Camellia) commonly grown in plant nurseries, traded by garden centers and cultivated in public and private gardens. The role of the plant trade in the dispersal of P. ramorum has been well documented, but there is a need for regional analyses of which environmental variables can predict disease expression in the trade and in the wild, so as to be able to better predict the further development of this worldwide plant health issue. In this study, we analyze data on the incidence of P. ramorum (2002–2009, thus before the reports in Japanese larch plantations) in counties in England and Wales as a function of environmental variables such as temperature and rainfall, controlling for confounding factors such as county area, human population and spatial autocorrelation. While P. ramorum county incidence in nurseries and retail centers was positively related to county area and human population density, county incidence in gardens and the wild did not show such correlations, declined significantly towards the East and was positively correlated with disease incidence in the trade. The latter finding, although not conclusively proving causation, suggests a role of the trade in the dispersal of this pathogen across English and Welsh landscapes. Combined together, P. ramorum county incidence in the trade and in the semi-natural environment increased with increasing precipitation and with declining latitude. This study shows the importance of environmental variables in shaping regional plant epidemics, but also yields results that are suggestive of a role of people in spreading plant diseases across entire countries.

P. ramorum in water workshop now on the web

Preventing the spread of Phytophthora ramorum via water was the focus of a 2 ½ day workshop in Puyallup, WA, June 28-30, 2011. Attended by over 50 regulators, researchers, and industry representatives from the western and southeastern US, as well as Washington, DC, the workshop's mission was to coalesce research, management, and regulations for effective, economical, and environmentally acceptable ways of limiting P. ramorum spread via contaminated nursery water runoff. The group began the meeting with a visit to the site of a previously positive Gig Harbor retail nursery (where P. ramorum-infested water had escaped the nursery and infected riparian salal plants) to review treatments and mitigations implemented. Meeting presentations addressed the incidence and distribution of P. ramorum detections in waterways, water baiting techniques, risks and impacts for WA, and treatments to reduce the risk of spreading inoculum in water. Research and education/outreach needs were identified, with group exercises and discussion concentrated on nursery treatments as well as water management, monitoring, and notification of downstream users of contaminated water. More information on the workshop can be found at: http://www.puyallup.wsu.edu/ppo/sod/extension/workshops/Pr_water_jun_2011/index.html. The meeting was organized by Gary Chastagner, Washington State University, and Susan Frankel, USDA-Forest Service, Pacific Southwest Research Station, and sponsored by Washington State University and the California Oak Mortality Task Force.

Colourful allure of sudden oak death

Sudden oak death doesn't sound pretty but snap it with the right camera, from the right angle, and it can look alluring. This forest in Cheshire, UK is one that's already known to suffer from sudden oak death, or Phytopthora ramorum. The firm APEM in Manchester used one of only two Leica RCD30 cameras in the world to photograph it from an aeroplane. With the ability to capture visible light and near-infrared, the 60 megapixel, £35,000 camera being tested as a method of diagnosing diseased trees. See it here: http://www.newscientist.com/blogs/shortsharpscience/2011/09/camera-reveals-tree-disease.html

Department gives update on Phytophthora ramorum Monitoring

The Department of Agriculture, Food and the Marine is continuing to survey forests and control outbreaks of the EU regulated plant disease Phytophthora ramorum, a fungus like organism that can damage and kill infected trees and plants. Under EU requirements, annual forest surveys for Phytophthora ramorum have been ongoing since 2003. Until last year, there had been no findings on tree species and P. ramorum had only been detected in forest areas on wild invasive rhododendron shrubs. Following the initial findings in Japanese larch in Ireland in July 2010, an extensive national aerial and ground survey was conducted. These forest surveys have now confirmed the disease in Japanese larch at eleven forest locations in five counties.

Japanese larch appears to be particularly susceptible to the disease, affecting all age classes and locally causing significant dieback and deaths. Noble fir, beech and Spanish chestnut growing in close proximity to the infected Japanese larch have also been found to be infected at a number of the sites and it is likely that the Japanese larch is the source of the infection. The infected trees are being removed to prevent the disease spreading.

Read more

Killer disease found in two new species of Irish tree

Two thirds of Northern Ireland's forests are under threat from a killer tree disease.

The fungal disease P. ramorum (often called Sudden Oak Death) has already infected tens of thousands of Japanese larch trees.

This has led to the felling of over 200 hectares across nine woodlands.

The disease may have jumped species and has infected a Sitka spruce in the Republic of Ireland and several beech trees in County Down, in the north.

If the disease spreads to other Sitka trees it could be a disaster for the Northern Ireland Forestry Service. The species makes up two thirds of all government-owned forests in Northern Ireland.

The disease was already known to be able to infect beech trees. It has also been confirmed that the infection has been found in European larch in England.

BBC News

Read more here

UK House of Lords debate on SOD

Trees: Sudden Oak Death — Question
House of Lords debates, 10 February 2011, 11:21 am

Lord Greaves (Liberal Democrat)

To ask Her Majesty's Government what action they are taking to counter the spread of sudden oak death in trees.

Lord Henley (Parliamentary Under Secretary of State, Environment, Food and Rural Affairs; Conservative)

My Lords, the Forestry Commission and the Food and Environment Research Agency, working in partnership with other organisations, are delivering a five-year programme in England and Wales against Phytophthora ramorum. The Government take this very seriously. Infected Japanese larch is being cleared from 7,920 acres of woodland in an effort to halt the spread of the disease.

The rest of the debate

Red alert in Britain's forests as Black death sweeps in

Just before Christmas, you could stand at the top of Crynant Forest in South Wales and not have a clue that there was a village in the valley below. Today, the view down to the little white houses is uninterrupted. Where in mid-December there were thousands of larch trees, now there is a mass of stumps and branches.

Read the rest of the article in The Telegraph. Ignore the parts about P. ramorum being "a lethal virus from Asia".

Forget trees, Welsh uplands needed for growing food

BRITAIN’S hill and upland areas could be the answer to tackling the growing threat of food shortages, according to a Mid Wales beef and sheep farmer.

John Pugh is calling on the Assembly Government to reconsider its ambitious tree planting strategy, which aims to create 100,000ha of new woodlands over the next 20 years, mainly on marginal hill land.

And he said any plantations cleared to combat Sudden Oak Death should be returned to farmland rather than replanted.

Read more in the Daily Post

Sudden oak death now threatens more of Britain's trees

After destroying millions of oaks in California, the infection spread to Britain – then suddenly jumped species

In woodlands around the UK, just as here in Afan Valley, south Wales, the race is on to fell thousands of trees in a desperate effort to contain a new disease which poses a threat to British forests on a scale not seen since Dutch elm disease wiped out millions of trees, changing the landscape of the country for ever.

Read the article here: The Guardian

Deadly P lateralis tree disease found at Loch Lomond

A deadly tree disease never seen in Britain before has been detected on the shores of Loch Lomond.

P. lateralis is a close relative of P. ramorum and is a root pathogen on Port Orford Cedar.

Read the rest of the article here:

http://www.bbc.co.uk/news/uk-scotland-11879891

P. ramorum spread to Northern Ireland

Tree killing disease spreads to NI

A private woodland and two government-owned forests in Northern Ireland have been devastated by an outbreak of a killer disease.

It has become known as Sudden Oak Death, but it is really a fungal-like infection that kills Japanese larch trees.

Read the rest of the article here:
BBC News

"Sudden Larch Death" in the UK

Plant pathology: Sudden larch death
Clive Brasier & Joan Webber
Nature 466:824–825
Date published:(12 August 2010)

doi:10.1038/466824a

An aggressive and unpredictable fungal pathogen is devastating larch plantations in Britain. Its remarkably broad host range, and the possibility of further geographical spread, give heightened cause for concern.

read the whole article here

Swansea Bay rally halted after tree disease

The Swansea Bay Rally, postponed last month due to a tree disease, has been cancelled for 2010, say organisers.

The event, due to start and finish outside Swansea Museum on 17 July, was called off at short notice.

The route, near Resolven and Rhondda, went through areas that have been hit by the Phytophthora ramorum infection, also known as as "sudden oak death".

Rally organisers said the event could not be re-scheduled to take other qualifying rounds into account.

The rally, which has been running for almost 40 years, is part of the MSA National Gravel Rally Championship.

Around 80 semi-professional and club drivers were due to take part.

read the whole article on BBC News