The insects' larvae cause serious damage to trees, and can kill them, by boring tunnels in the trunks and branches as they eat their way through the wood, before emerging as mature beetles. Not native to the UK, Asian longhorn beetle (ALB) and its larvae pose a serious threat to a wide range of broadleaved trees and shrubs such as maple, sycamore, elm, horse chestnut, willow, poplar, birch and some fruit trees
The UK's first outbreak of breeding ALB was found earlier this year in the Paddock Wood area of Kent. As tree felling work to eradicate this outbreak is nearing completion, The Food & Environment Research Agency (Fera) and the Forestry Commission are asking the public to look out for these distinctive beetles during the emergence season, both in the Kent area and across the UK, to help prevent any outbreaks in the future.
Fera plant health policy head Martin Ward said:
"Although we are cautiously optimistic that we can successfully eradicate the Paddock Wood outbreak, we cannot afford to be complacent.
"At this time of year any larvae hidden undetected within trees or in the wood of boxes and crates will develop into beetles and lay eggs on other trees in the surrounding area. The public can really help us by keeping a lookout for these highly distinctive beetles, and reporting any findings.
"And we are not just asking people in the Paddock Wood area to look out for them - these pests could turn up anywhere in the UK, especially where plants, and goods in wooden packaging, are received from China and Korea. All reports will be assessed by Fera's Plant Health and Seeds inspectors and followed up as appropriate."
Sixty-seven trees have been found infested in the Paddock Wood area to date, and more than 250 live larvae have been found inside these trees.
Action to fell all trees showing signs of infestation, and precautionary felling of all at-risk tree species within the demarcated infestation zone, have resulted in the removal and incineration on site of more than 2000 trees.
The most recent finding of larvae was more than 20m up a tree and therefore undetectable without felling the tree, demonstrating the need for precautionary felling of all potential host tree species in the infestation area to give the best chance of successfully eradicating the outbreak. It is expected that the felling work will be completed by mid-August if there are no more finds. All felled material is being held locally for inspection before being incinerated on site.
The Forestry Commission has been co-ordinating the tree felling work in the Paddock Wood area, and Forestry Commission plant health service head Dr John Morgan said: "It is always regrettable when we have to fell large numbers of trees to keep the UK free of invasive pests or disease and protect much larger numbers of trees. We have been extremely fortunate that local residents and landowners have worked with us to eradicate this outbreak."
Leaflets are being distributed in the Paddock Wood and East Peckham area up to 2km (1.25 miles) from where the original outbreak was found. These include a picture of the beetle and details of what to do if one is spotted. The beetles are large (about 20 - 40mm / 0.75 - 1.5 inches long) and black with variable white markings. Their antennae are particularly distinctive, being very long (about twice as long as the body) with black and pale blue or white bands.
Horticultural and forestry authorities are also keen for anyone receiving trees and plants from China and Korea, or goods in wooden boxes and crates from those countries, to be extra vigilant for signs of the distinctive beetles emerging from the plants or boxes, and to report them immediately.
Anyone who suspects they have seen an Asian longhorn beetle, or evidence of its presence, must contact the Fera Plant Health Helpline by either:
*telephoning 0300 1000325;
*emailing firstname.lastname@example.org ; or
*via the new reporting app on Fera's website at http://albwatch.fera.defra.gov.uk.
Digital photographs may be sent with email reports to aid identification.
If possible, the beetle should be caught and placed in a secure container such as a sealed glass jar so that an inspector can collect it. The beetles are harmless to humans, although they should be handled with caution because they can nip the skin.
Further information is available from
www.fera.defra.gov.uk/asianlonghornbeetle and www.forestry.gov.uk/asianlonghornbeetle.