Asian spotted longhorn beetle

Taxonomic position. The Asian spotted longhorn beetle (Anoplophora macularia) belongs to the order Coleoptera and the family Cerambycidae. This wood-boring insect is closely related to other species of the genus Anoplophora, known for their invasive potential and ability to cause extensive damage to hardwood trees in various temperate climate zones.

Host plants. This beetle is a polyphagous pest, meaning it attacks a wide variety of deciduous tree species. Preferred hosts include genera such as Acer (maple), Populus (poplar), Salix (willow), Betula (birch), and Fraxinus (ash). In addition to forest and landscape trees, the beetle can impact commercial fruit-bearing trees, posing an economic threat to orchards.

Biology and life cycle. The life cycle of Anoplophora macularia typically spans one to two years, depending on the environment. Adult females chew small pits into the bark to deposit eggs. Upon hatching, the larvae bore into the inner bark and eventually into the heartwood. They spend most of their life cycle feeding inside the tree, undergoing several larval instars before pupating and emerging as adults through characteristic circular exit holes.

Damage and economic impact. The larval stage is the most destructive. Larvae excavate galleries within the xylem and phloem, disrupting the tree's vascular system. This damage results in nutrient deficiency, canopy dieback, and eventually structural failure of the tree. The presence of the pest is often indicated by piles of coarse frass at the base of the trunk and small, rounded exit holes on the surface of the bark or branches.

Control measures. Due to the larvae's protected position within the wood, eradication is extremely difficult once an infestation is established. Management strategies rely on:

• Strict quarantine regulations to prevent the movement of infested firewood, logs, and nursery stock.
• Early detection surveys using visual inspections for exit holes and frass.
• Removal and destruction of infested host trees to reduce the beetle population.
• Use of targeted insecticides on the trunk during the adult flight period to prevent egg-laying.