Asian Longhorn Beetle found in Kent

Asian Longhorn Beetle

An outbreak of the Asian longhorn beetle (ALB), an exotic beetle pest which could have severe consequences for British trees, has been found in Kent, the Food & Environment Research Agency (Fera) confirmed today.

This is the first time an outbreak of this pest has been found in the UK, and it is being treated extremely seriously. Fera and the Forestry Commission are taking urgent steps to try to eradicate the outbreak before it has the chance to spread further afield.

Several larvae of the beetle were found inside a poplar tree during a routine survey by the Forestry Commission at a site in the Paddock Wood area. Scientists from the Commission's Forest Research agency had been monitoring an area around the site where an adult beetle had been found in 2009, and this is the first evidence of infestation. It is thought the beetles originated from wood packaging used to import stone from China at an adjacent industrial site.

The beetle is not native to the UK, and poses a serious threat to a wide range of broadleaved trees and shrubs such as maple (including sycamore), elm, horse chestnut, willow, poplar, birch and some fruit trees.

Speaking about action to eradicate the outbreak, Martin Ward, Head of Plant Health Policy at Fera, said,

“Our plant health inspectors and the Forestry Commission are conducting a survey to determine the extent of this outbreak. They will be contacting all those within the survey area over the next few days and weeks with a view to inspecting all potential host trees for signs of the beetle. In the meantime we would urge members of the public, local businesses and landowners to be on the alert for the beetle and let us know if they find anything.”

Adult beetles are large (about 20 - 40 mm long) and shiny black with variable white markings. Their antennae are particularly distinctive, being much longer than their bodies (up to twice the body length) and are black with white or light blue bands. The larvae of the beetle feed undetected on the inside of the plant, and can kill it or leave it weakened and susceptible to further pest and disease damage.

The most obvious symptoms of ALB damage are the circular adult exit holes, which are about 10 mm in diameter and are generally found in the main trunk and above. The adult beetles usually emerge from these holes between May and October.

Dr John Morgan, Head of the Forestry Commission's Plant Health Service, said,

“It’s difficult to say exactly what measures will need to be taken until we have completed the initial survey work to determine the extent of the outbreak. However, we will need to remove any trees found to be infested, and it is possible that we will need to remove potential host trees around the original site as a precautionary measure. Eradication measures to treat outbreaks in the US and Italy have resulted in the loss of tens of thousands of mature trees.”

Anyone who suspects they have seen an Asian longhorn beetle, or evidence of its presence, should contact the Fera Plant Health Helpline on 0844 248 0071 or email planthealth.info@fera.gsi.gov.uk If possible, the beetle should be caught and placed in a secure container so that an inspector can collect it. The beetles are not harmful to humans, although they should be handled with caution because they can nip the skin.

More-detailed information about ALB can be found on the Forestry Commission’s website.