The Plant Health Department is on the lookout for the citrus longhorn beetle (anoplophora cinensis), a damaging quarantine pest of a range of trees and shrubs. Although the insect is not present in Malta, the department is monitoring for any symptoms of the beetle, to ensure against its introduction here, or so that necessary action would be taken immediately if it is accidentally introduced.

The natural range of the beetle includes China, Japan and other countries in South East Asia. But these beetles have been moving around the world on ornamental trees imported from Asia. They are a threat to horticulture, forestry and also to citrus production in the Mediterranean. Worth mentioning, the department said, is the outbreak of the beetle that occurred in Lombardy, Italy. Eradication measures have included the destruction of hundreds of mature trees.

Adults of the citrus longhorned beetle are large (21–37 mm long) and black with variable white markings. Their antennae are longer than their bodies and are black with white/light blue bands. These beetles spend most of their life (ranging from one to two years, in Asia), as larvae inside a trunk or root, so there can be little or no sign of their presence to anyone inspecting a host tree.

The most obvious symptoms of the damage caused by these insects are adult exit holes which are typically 6-11 mm in diameter and are generally found towards the base of trunks. The pest is most likely to be seen in July and August, but interceptions have occurred as early as May and as late as October.

The Plant Health Department encouraged the public to immediately report any suspicion of the presence of the pest and its symptoms. Further details on the biology and symptoms of the insect can be found on the Plant Health Department’s website on www.planthealth.gov.mt. Any suspicions should be reported on 2590-4312 or 2339-7222/3.