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Citrus longhorn beetle (Anoplophora chinensis)

 

Citrus longhorn beetle (Anoplophora chinensis)

The citrus longhorn beetle (Anoplophora chinensis) is a non-native pest which is extremely damaging to a wide range of broadleaved trees and shrubs. It is a quarantine pest for the European Union. Its natural range includes China, Japan and other countries in South-East Asia. Citrus longhorn beetles have been moving around the world in ornamental trees from Asia, and pose a serious threat to horticulture, forestry and native trees in the UK.

The threat

There are no known outbreaks (breeding populations) of the beetle in the UK. However, there have been numerous interceptions of individuals here since 2005, as well as in Europe, demonstrating that there is a significant threat to the UK.

Symptoms

Adult beetles are large and black with variable white markings. Their antennae are particularly distinctive: they are longer than their bodies (between 1.2–2 times the body length) and black with white or light blue bands. The larval stage of the beetles is the most damaging, because the larvae feed internally on the pith and vascular systems of the lower trunk and root.

The tunnels created by the feeding leave trees susceptible to diseases and wind damage. The adults can cause more-limited damage by feeding on foliage and eating young bark. Citrus longhorn beetles spend most of their life as larvae inside a trunk or root, and hence there can be little or no external sign of their presence to anyone inspecting a host tree.

Citrus longhorn beetle (Anoplophora chinensis) showing exit hole in branchHowever, adult beetles make a distinctive hole (pictured) in the trunks or branches when they emerge at the end of the larval stage.

 

 

 

Pictures courtesy of Fera Science; photographer David Crossley FBIPP QEP; Crown copyright

Identification

This factsheet provides a guide to identifying citrus longhorn beetle.

Note that it is very similar in appearance to Asian longhorn beetle.

Lifecycle

Their lifecycle can last one to two years in Asia, but in the UK the lifecycle is likely to be at least two years long, and more likely three or more years, as in the Netherlands.

Susceptible trees

Citrus longhorn beetle has an extensive host range of deciduous trees and shrubs, including many species native to the UK, species of forestry concern, and species grown as ornamentals. In 2008, the Eurpean Commission passed emergency measures aimed at preventing the introduction to, and spread of this pest within, the EU.

The decision referred specifically to the following trees and shrubs which are known to be the most significant hosts of citrus longhorn beetle: apple (Malus species.), alders (Alnus spp.), beech (Fagus), birch (Betula), cherry (Prunus), citrus spp., Cotoneaster spp., elm (Ulmus), hazel (Corylus), hornbeam (Carpinus), horse chestnut (Aesculus), Lagerstroemia spp., maples (Acer), pear (Pyrus), plane (Platanus), poplar (Populus), and willow (Salix.).

More information (Fera website)

Reporting suspected cases

 

Tree Alert iconIf you think you have spotted the beetle please tell us using Tree Alert

 


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Last updated: 6th February 2018