New Beetle Threat Detected in Britain

Local growers and gardeners should be vigilant following the discovery of a harmful type of beetle, which is new to the British Isles

An invasive non-native insect which could harm local woodland areas and garden plants has been identified in Britain. The Citrus Longhorn Beetle (Anoplophora chinensis) has been brought in on Acer plants (Acer palmatumor ‘Japanese Maple’) imported from China via the Netherlands and distributed by mail order. This pest is not established in Great Britain but there have been several recent findings in different parts of the country. There have been no findings as yet in Northern Ireland.

Although the beetle is known to have been introduced in Acers, it can affect a wide range of trees and shrubs, such as oak, beech, ash, maple, apple, pear, willow, hibiscus, horse chestnut, hornbeam, hazel, birch, mulberry and rose. Citrus Longhorn beetles develop inside plant stems and tree trunks, taking between one and three years to emerge, and are therefore difficult to detect. However exit holes may be visible where the adults have emerged from the stem.

These large black beetles grow to between 21-37mm long and have distinct white markings and long ‘horns’ or antennae. The antennae are longer than the body and are black with white bands. It could be found on a wide range of trees or shrubs.

If you see one of these distinctive beetles, please isolate it in a sealed container and contact DARD Quality Assurance Branch on 028 9054 7106 or email: qab.admin@dardni.gov.uk

Notes to Editors

1. Prior to emergence, there are no obvious symptoms of infestation or the presence of a larva or pupa within a plant or tree. However, large (6-11mm) exit holes are left by the emerging adults in the stem. These exit holes may be just above ground level, but can also be just below ground level and in such cases are not visible. Other symptoms can include:

• Scraped sections of bark
• Chewed leaves and damage to the petioles by adults
• T-shaped egg slits in bark
• Saw-dust like ‘droppings’ or wood pulp around holes and larval tunnels in the wood under loose or thin bark. Examination of the ground at the base of the shrub or tree for signs of wood shavings provides a rapid method of detecting activity of late stage larvae.

2. Further information about the Citrus Longhorn Beetle is available on the DEFRA website

3. All suspect alien invertebrate plant pests must be reported to DARD Quality Assurance Branch, Magnet House, 81-93 York Street, Belfast, BT15 1AD, telephone 028 9054 7106. Email:qab.admin@dardni.gov.uk

4. All media queries to DARD Press Office on 028 9052 4619. Out of office hours, contact the Duty Press Officer via pager number 076 9971 5440, and your call will be returned.