Citizen science survey to monitor threats such as oak processionary moth and ash dieback disease
Members of the public are being asked to spot the "six most unwanted" pests and diseases threatening UK trees, as part of a citizen science survey starting on Thursday.
Recent outbreaks of the oak processionary moth and ash dieback disease have added to the increasing number of pests and diseases that have been attacking trees in the past few years, leading to a decline in tree health and in some cases tree loss.
In order to manage the threat, Open Air Laboratories (Opal) researchers, together with experts from the Food and Environment Research Agency (Fera) and Forest Research, are asking the public to get involved in their national tree health survey which runs from May to September when trees are in leaf.
Survey activities include identifying trees, measuring their girth and height, examining the trunk, branches and leaves for signs of poor health and recording the presence of pests and diseases.
The survey includes a guide to six of the most unwanted pests and diseases that could spell disaster for trees and forests if they spread across the UK, such as Chalara dieback of ash (Chalara fraxinea) and pests like the oak processionary moth (Thaumetopoea processionea).
The findings will contribute to a national research programme that is investigating the health of Britain's trees and the spread of pests and diseases.
Joan Webber, principal pathologist at Forest Research, said: "Input from across Great Britain will help us to develop a comprehensive picture of tree health and contribute to the database of information that we are building."
Last week the Forestry Commission urged the public to help stop the spread of the oak processionary moth that devastates oak trees and whose caterpillars can cause serious health problems. A native of southern and central Europe, the species has become established in south-west London and parts of the home counties since being found in England in 2006. The commission is planning to use a helicopter to blanket-spray woodland with insecticide.
Britain's 80 million ash trees remain at deadly risk from ash dieback caused by Chalara fraxinea, a virulent fungal disease that has swept across Europe. Scientists have successfully unravelled the genetic code of the fungus that causes the disease, which causes the crown of the tree to die back and leaves to turn brown. Latest figures from the Forestry Commission reported a total of 490 sightings in nurseries, plantations and established woodland around the UK.
More than half a million people have joined the Open Air Laboratories (Opal) citizen science project, designed to get people outdoors and involved in scientific research, since its launch in 2007.
Six most unwanted
Pests and diseases that could have a serious impact on the UK's trees
Asian longhorn beetle (Anoplophora glabripennis)
Not yet established in the UK, but would be a major threat to a wide range of broadleaved trees. Beetles are black and shiny with long antennae. Larvae tunnel internally through trunks and branches. A major outbreak in Kent in 2012 saw 2,000 trees felled.
Citrus longhorn beetle (Anoplophora chinensis)
Black with variable markings and long antennae. Not present in the UK, but a few that reached the UK on trees imported from China, Japan and South Korea were intercepted before reaching the wider environment. Would cause a major threat to broadleaved trees.
Chalara dieback of ash (Chalara fraxinea)
Limited distribution in the UK since being found in 2012 but has already infected large numbers of ash trees across Europe. Affected trees have diseased leaves, trunk lesions and thinning crowns.
Emerald ash borer (Agrilus planipennis)
Metallic green beetle with burrowing larvae that causes thinning and yellowing of foliage and fissures in the bark. Not present in the UK, but the increase in the global movement of wood and wood packaging poses a significant risk of its accidental introduction. Affects ash trees.
Oak processionary moth (Thaumetopoea processionea)
First found in oak trees imported from continental Europe in west and south-west London in 2006. By July 2012, it had been found in south London and Berkshire. The caterpillars march in nose-to-tail processions when feeding and can strip trees bare. They are covered in toxic hairs that can lead to skin irritation and allergic reactions.
Pine processionary moth (Thaumetopoea pityocampa)
Caterpillars have orange brown backs with blueish-grey bands and build nests that form white silken clumps near the tops of pine trees. Since the 1990s the pest has been moving north through France and is now breeding near Paris; it could spread to the UK. Also covered in toxic irritating hairs.
• You can download or request your free survey pack, including tree identification guide, field notebook, field guide and "six most unwanted" card from OPALexplorenature.org