Imported Christmas trees could be providing shelter to a host of new pests and diseases entering the UK, according to a new report.
The report, published by Grown in Britain, uses data collected by the DEFRA Plant Health Risk and Horizon Scanning Team to identify fifteen potential pests that have the potential to enter the UK on imported Christmas trees under 3m tall. Larger trees posed more of a risk and have the potential to harbour a further 15 different species of pests.
Common Christmas tree species include:
Significant threats include the Siberian fir woolly aphid, the pine processionary moth and the fungus blight of pine. These are currently absent from the UK.
The pine processionary moth is currently menacing the pine trees of southern Europe. The larvae feed on pine needles, which can ultimately kill the tree. They are also a danger to human health, causing irritation to the skin, eyes and throat. They have been identified as far north as Paris.
The caterpillar of the pine processionary moth (Thaumetopoea pityocampa)
Grown in Britain Chief Executive Dougal Driver says: 'Christmas trees provide ideal conditions for pests to hitch a ride. The trees are usually netted, which means the branches don’t dry out, and pests can remain hidden in the tightly bound branches. With climate change, the risks are also rising, as pests which are native to warmer parts of Southern Europe are increasingly likely to be able to survive in Northern Europe and the UK.'
As of December this year, new Plant Health Regulations will change the way plant passports are issued. Plant passports can be authorised by businesses that are regularly inspected by the plant health authority. The new regulations may mean that more Christmas trees are required to have them.
Currently, cut pine trees below 3m tall are not currently controlled and require no passports, unless they have originated from an area where the pine wood nematode is known to be present.
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To combat the problem, Grown in Britain has developed a Christmas tree certification scheme, which currently covers around 100,000 trees. Certification is granted if the trees have been grown in this country and have been subject to regular biosecurity checks.
'I welcome Grown in Britain’s initiative to encourage people to source their Christmas trees responsibly and practice strong biosecurity.' Commented Professor Nicola Spence, the UK Chief Plant Health Officer: 'Protecting our country from pests and diseases is vital to safeguard our environment, economy and health. Our international surveillance work helps us spot new risks and take action to stop any diseases before they arrive.'