Citrus longhorned beetle

Systematic position: The citrus longhorned beetle (Anoplophora chinensis) is a dangerous invasive pest from the order Coleoptera, belonging to the family Cerambycidae. Due to its ability to kill healthy trees and spread rapidly through trade, it is classified as a high-priority quarantine pest in many regions of the world.

Affected plants: This beetle is a highly polyphagous insect. It attacks a wide range of deciduous trees, including maple, horse chestnut, apple, pear, willow, poplar, linden, plane, and citrus trees. It poses a severe threat to nurseries, urban plantings, and fruit orchards alike.

Biology and life cycle: The life cycle usually spans from 1 to 3 years. Female beetles chew holes in the bark of the lower trunk or exposed roots to deposit eggs. The larvae hatch and tunnel into the heartwood, feeding on the vascular tissue. After development, they pupate inside the trunk, and emerging adults chew their way out, creating distinctive circular exit holes.

Damage and harmfulness: The primary damage is caused by the larval stage feeding within the wood. This activity disrupts water and nutrient transport, leading to canopy dieback, wilting, and eventually the death of the tree. Indicators of infestation include sawdust (frass) accumulation at the base of the tree and visible exit holes on the trunk.

Management and control: Control is extremely difficult once a tree is infested. Strategies primarily focus on prevention: strict plant quarantine regulations, systematic surveillance of host trees, and the use of pheromone traps for early detection. If an infestation is confirmed, affected trees must be felled, chipped, and burned to kill the developing larvae and prevent the spread of adult beetles.