English name: Citrus Longhorn Beetle
Nordic names: Asiatisk citrustræbuk (DK), Asiatisk långhorning (SE)
Estonian name: Hiina sikk
Major host plants
The most significant hosts of A. chinensis are Acer spp. (maples), Populus spp. (poplar), Salix spp. (willow), and Platanus spp. (plane). Other hosts include Aesculus hippocastanum (horse chestnut), Alnus spp. (alder), Betula spp. (birch), Carpinus spp. (hornbeam), Citrus spp., Corylus spp. (hazel), Cotoneaster spp., Fagus spp. (beech),Lagerstroemia spp., Malus spp. (apple), Prunus spp. (cherry etc.), Pyrus spp. (pear), and Ulmus spp. (elm).
Prior to emergence, there are no obvious symptoms of infestation or presence of larvae or pupae within a plant or tree. However, large (6-11mm) exit holes are left by the emerging adults in the stem just above (or below) ground level. Other symptoms include piles of sawdust-like frass or wood pulp around holes, and larval tunnels in the wood under loose or thin bark.
Origin: China. From here spread into other countries in South-East Asia, USA and Europe.
A map can be downloaded from Eppo's website. See instructions here.
Soon after emergence, the adults feed on leaves, petioles and young bark of host trees. Most activity, including feeding and mating, occur during day time. The eggs are laid one by one under the bark of the trunk through a T-shaped oviposition slit, from just above the soil surface to 60 cm above. The young larva hatches out in one to three weeks and initially feed on green, sappy portion of the inner bark. During later instars, the larva forms tunnels in the branches and trunk just under the bark and later enters the woody tissues of the lowest portions of the trunk and roots. Pupation takes place in the wood, often in the upper part of the feeding area. The pupal stage lasts four to six weeks until a pre-adult is formed with the final molt. The pre-adult is inactive and develops to mature in about one to two weeks and emerge from the tunnel. This occurs from spring to late summer. The duration of the life cycle of A. chinensis is one to two years (maybe up to three years) depending on the climate and feeding environment.
The adults fly readily. In international trade most likely to move as eggs, larvae or pupae in woody planting material, including bonsai plants, and possibly in packing material. Larvae and adults have entered Europe on bonsai plants of Acer, Celastrus, Cydonia, Malus, Sageretia from China and Japan, and have been found in unheated glasshouses and out of doors, damaging trees and shrubs in summer.
Detection and Inspection
Bark around the base of trees should be examined for an ovipositional scar. Especially at the base of trunks, and any exposed roots, should be inspected for signs of larval tunnels. Frass and wood pulp extruding from holes are signs of infestation.
Pest status and importance
A. chinensis can cause serious damage to fruit, ornamental and amenity trees. Trees are weakened by larval attack and become more readily susceptible to diseases and wind damage. They may often be killed. Damage to small young trees is most serious.
Source of information
See further information here:
Author: Jorma Rautapää
Editor: Elise T. Yamamoto Buch