Taiwan fig weevil

The Taiwan fig weevil (Aclees taiwanensis) is a highly destructive invasive pest belonging to the order Coleoptera, family Curculionidae. Originally native to Southeast Asia, this insect has recently spread to various Mediterranean regions, where it poses a significant threat to fig tree (Ficus carica) production and survival.

The primary host plant is the fig tree. Both adults and larvae contribute to the damage, although in different ways. Adult weevils feed on leaves, buds, and young bark, but the most severe damage is inflicted by the larvae, which bore into the woody tissues of the trunk and branches, compromising the tree's internal structure.

The life cycle begins when a female lays eggs in slits carved into the bark at the base of the tree. The larvae hatch and immediately tunnel into the wood, where they feed and grow. They complete their entire larval development inside the tree, creating long, complex galleries. After pupation, the adults emerge through exit holes to repeat the cycle.

The presence of the pest is often identified by the accumulation of frass (sawdust-like wood waste) at the base of the trunk. Infested trees show symptoms such as branch dieback, yellowing foliage, and structural weakness. In severe cases, the tunnels created by the larvae destroy the vascular system, causing the tree to dry out or snap under heavy winds.

Effective management of Aclees taiwanensis requires an integrated pest management (IPM) approach:

• Regular monitoring for entry/exit holes and frass on the trunk base.
• Manual removal and destruction of heavily infested plant parts.
• Application of entomopathogenic nematodes injected into larval galleries.
• Use of systemic insecticides targeted at adult beetles during peak activity.
• Strict quarantine measures to prevent the introduction of infested wood or plants.