Asian Longhorn Beetle outbreak in Kent - native broadleaved trees threatened

Tuesday, 3 April, 2012


An outbreak of an exotic beetle in Kent could have severe consequences for UK trees the Food and Environment Research Agency (fera) has warned. The discovery is being taken extremely seriously and steps have already been made to eradicate the beetle before it can spread to other parts of the UK.


Seven Asian Longhorn Beetle (ALB) larvae were found inside a poplar tree during a routine survey by the Forestry Commission at a site near the village of Paddock Wood. Forest Research had been monitoring an area around the site where an adult beetle had been found in 2009 and this is the first infestation discovered to date. It is thought the beetles were imported in wood packaging containing stone from China.

The non-native beetle poses a considerable threat to a wide range of broadleaved trees and shrubs such as sycamore, elm, horse chestnut, willow, poplar, birch and some fruit trees.

Speaking about proposals to contain 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 around 20 - 40 mm long, shiny black with white markings. Their antennae are up to twice the body length and are black with pale 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 c. 10 mm diameter exit holes  often found in the main trunk and branches. The adult beetles usually emerge from these holes between May and October.

Head of Plant Health at the Forestry Commission, John Morgan, stated "Until we have completed the initial survey work to determine the extent of the outbreak it's difficult to say exactly what measures will need to be taken. 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."

If anyone suspects they have seen an Asian Longhorn Beetle, or evidence of its presence, please contact the fera Plant Health Helpline 0844 2480071 or email [email protected] If possible, the beetle should placed in a secure container so that an Inspector can collect it. The beetles are not harmful to humans, though they should be handled with caution as they can bite.