Extension of infestation zone for exotic beetle pest outbreak in Kent

Issued jointly with Fera

As a result of the felling programme being carried out in response to the UK’s first outbreak of Asian longhorn beetle, an infested tree has been confirmed towards the northern limit of the current infestation zone. This means that the zone has been extended by a further 100 metres, requiring additional felling within the extended area.

Larvae were discovered in the tree concerned after it had been felled, confirming the need to fell and inspect potential host trees in the infestation zone. Survey work to date has confirmed that 65 trees in the zone have been found to be infested, and more than 1300 infested and potential host trees have been felled. Removal and incineration of trees from the extension area is expected to begin this week. The felling operation in this area should be complete by the end of June.

The most recent findings were young larvae (grubs) which would not have reached the stage by this summer when they could develop into adult beetles and fly off into the surrounding area. It also suggests that the eggs were laid last year, rather than earlier, supporting the view that the tree is close to the limit of the infested area. This means that there remains a good chance that the outbreak can be contained and eradicated, although further survey work will be necessary to confirm the position.

In the meantime, anyone who suspects they have seen an Asian longhorn beetle or evidence of its presence must contact the Fera Plant Health Helpline 0844 2480071 or email planthealth.info@fera.gsi.gov.uk. If possible, the beetle should be caught and placed in a secure container for collection by an inspector. The beetles are not harmful to humans, although they should be handled with caution because they can nip the skin.

More detailed information is available on the Forestry Commission and Fera websites at www.forestry.gov.uk/asianlonghornbeetle and www.fera.defra.gov.uk/asianlonghornbeetle.

Follow news about tree pests and diseases at www.twitter.com/treepestnews .

Notes to Editors:

1. Eradication action involves the felling of all trees of species known to be hosts of ALB within the infested zone, including those with symptoms of infestation and those not showing symptoms. All felled material is being held locally for inspection before being incinerated on site.
2. Known host tree species include  maples and sycamores (Acer), horse chestnut (Aesculus), Mimosa or silk tree (Albizia), alder (Alnus), birch (Betula), hornbeam (Carpinus), katsura (Cercidiphyllum japonicum), hazel (Corylus), beech (Fagus), ash (Fraxinus), Koelreuteria paniculata, plane (Platanus), poplar (Populus), cherry and plum (Prunus), false acacia/black locust (Robinia pseudoacacia), willow and sallow (Salix), pagoda tree (Sophora), mountain ash and whitebeam (Sorbus), American pin oak (Quercus palustris), North American red oak (Quercus rubra), and elm (Ulmus).
3. Residents and landowners within the 2km buffer zone are being asked to hold back from any felling, tree surgery or pruning of woody shrubs in gardens. This is because the beetle’s larvae live in trunks and branches, so it is important to make sure these are properly disposed of. Any residents who do need to prune or fell trees or woody shrubs have been asked to ensure that all woody material is taken to an appropriate Kent County Council waste transfer station or recycling site.
4. ALB (Anoplophora glabripennis) has been spreading around the world hidden in timber imported from China, notably wood packaging material such as crates and dunnage (wooden blocks used to prevent cargo moving about in ships). ALB is a serious pest in China, where it has killed millions of poplar trees planted to prevent soil erosion. In the USA, $0.7 billion have been spent on campaigns to eradicate it.
   A range of deciduous trees in the UK could be hosts, although all the interceptions in the UK until the present outbreak have been found to come from wood packaging material. The beetles are large (20-40mm long) and distinctive, being shiny black with white markings. They also have very long, black antennae ringed with pale blue or white markings. They are almost identical in appearance to Citrus longhorn beetle (Anoplophora chinensis), another non-indigenous longhorn beetle which threatens trees in Britain. Fera has produced a video on the Citrus longhorn beetle which can be viewed at
   www.fera.defra.gov.uk/plants/plantHealth/pestsDiseases/clb/clbVideo.cfm
5. The adult beetles scrape away a portion of bark on a host tree to lay their eggs just underneath. The lifecycle from egg to beetle is one to two years in Asia, possibly longer in the UK. Although the larvae are unlikely to emerge as adult beetles before the end of June in the UK, it is important that all infested and potentially infested trees are removed as early as possible before then. Beetles emerge, then mate and lay eggs, after which they die. When the larvae hatch, they feed by boring in the main trunk and branches, which makes them difficult to detect. The most obvious symptoms of ALB damage are the circular adult exit holes, which are about 10mm in diameter and are generally found in the main trunk and branches. Other signs which can be present, but are much less obvious, include piles of sawdust-like droppings at the base of infested trees, scraped bark, sap bleeding from the sites where eggs have been laid, and bark feeding damage on smaller branches and shoots. Not only do the larvae cause structural damage to trees, but this damage also leaves the tree susceptible to other diseases. Eventually this can lead to the death of the tree. 
6. Analysis of climate data by Fera scientists suggests that most of England and Wales and some warmer coastal areas of Scotland are suitable for beetle establishment, but south-east England and the south coast are at greatest risk.
7. The Forestry Commission is the government department for forestry in Great Britain, and works to improve the lives of people through the many benefits that sustainably managed trees, woods and forests can provide. www.forestry.gov.uk
8. The Food & Environment Research Agency (Fera) is an Executive Agency of the UK Government’s Department for Environment, Food & Rural Affairs (Defra). Its remit is to provide robust evidence, rigorous analysis and expert professional advice to government, international organisations and the private sector, in order to support and develop a sustainable and secure food chain, a healthy natural environment, and to protect the global community from biological and chemical risks. www.fera.defra.gov.uk

MEDIA CONTACTS:

• Fera - Alison Wilson, 01904 462380; alison.wilson@fera.gsi.gov.uk
• Forestry Commission - Charlton Clark: 0131 314 6500