Spurge bark beetle

Systematic position: Thamnurgus characiae belongs to the order Coleoptera and the family Curculionidae, specifically the subfamily Scolytinae. Unlike most bark beetles associated with trees, this species has evolved to inhabit the stems of herbaceous plants, making it a unique specialist pest.

Host plants: The beetle is primarily associated with various species of the genus Euphorbia. It is of particular concern for horticulturalists growing Euphorbia characias and related Mediterranean spurges, as it can cause localized destruction of ornamental plantings.

Biology and life cycle: The insect completes its life cycle within the host plant's stem. Adult beetles bore into the stem, where mating and oviposition occur. Larvae develop internally by feeding on the pith, which provides a sheltered environment that makes them less susceptible to contact-based pesticides.

Nature of damage and harm: The feeding activity of larvae and adults disrupts the vascular flow within the stems. This typically leads to chlorosis, wilting, and eventually the death of the affected stems. Heavy infestations can lead to a significant decline in the health and aesthetic value of the plant.

Protection measures: Management of Thamnurgus characiae relies heavily on integrated pest management practices:

• Regular monitoring of Euphorbia stems for entry holes or signs of wilting.
• Sanitary pruning and immediate removal of infested stems to prevent population spread.
• Systemic insecticides may be used during the flight period of adults, provided they are applied to reach internal tissues.