Citrus longhorn beetle (Anoplophora chinensis)

The citrus longhorn beetle (Anoplophora chinensis) is a serious invasive pest that is found in South East Asia. It is listed in the Plant Health Directive and a specific EC Decision is in place to minimise the risk of introductions and to control any findings. Citrus longhorn beetles can infest a very wide range of broadleaved trees and would be a major threat to horticulture and the wider environment if they became established. The larvae feed undetected on the inside of trees leaving them weakened and susceptible to further pest and disease damage. Most of the citrus longhorn beetles that have been found to date in the UK have been associated with Japanese maple trees imported from China.

In 2008 citrus longhorn beetles were found in private gardens in the UK as well as on a nursery in Guernsey. The findings were on maple trees (Acer palmatum) imported from China via The Netherlands in January 2008 and distributed by mail order.

There were further findings in 2009 with two citrus longhorn beetles caught emerging from maple trees in private gardens. Both findings were on trees purchased over the last three years and were reported by members of the public to Fera's Plant Health and Seeds Inspectorate (PHSI). In 2010 an outbreak has been confirmed in Boskoop, a major nursery growing area in the Netherlands. Fera's surveillance programme for the pest is focused particularly on host plants from this affected area, as well as those imported from countries outside the EU where the pest is established. Due to the serious nature of these findings, Defra is asking that members of the public look out for this beetle, which may emerge from infested plants that have been distributed

Outbreak in the Netherlands

Tuesday 16th February 2010

Following an outbreak of the damaging pest, citrus longhorn beetle, in the Boskoop area of the Netherlands, the Dutch Plant Protection Service is carrying out inspections of the 500+ nurseries which fall within a 2km area. They are publishing details of nurseries which have been inspected and have resumed trading and also those which are not currently growing host plants of citrus longhorn beetle.

While the pest has not been identified to date in these nurseries, given the difficulties of detecting it and evidence to suggest that it may have been present in the area for a number of years, there is a risk that plants may have been unwittingly supplied with the pest present. Given the volume of plants received in the UK from the Netherlands and particularly the Boskoop area, and the period that the pest may have been present in that area, it is impossible to facilitate a specific tracing exercise. However, those in the horticulture industry as well as individuals are recommended to be vigilant for signs of the pest on any woody deciduous plant, particularly Japanese maple (Acer palmatum), irrespective of origin. Details about the pest and evidence of its presence are available here. If you have any suspicions, please contact your local Plant Health and Seeds Inspector.

In response to these developments, Fera will be stepping up its monitoring programme of plants originating from Boskoop. Fera's Plant Health and Seeds Inspectorate already undertake surveillance at a range of premises involved in growing and trading plants. In liaison with the companies involved, inspections will be undertaken of the main host plants which are known to derive from the Boskoop area, or where there are concerns about the plant health status of the plants. Such inspections will include destructive sampling, which is the most effective means of detecting the pest. Destructive sampling is also being carried out routinely on all consignments of the main hosts imported directly from outside the EU. The need for additional action will be kept under review in the light of developments.