Ambrosiodmus lewisi

Systematic position. Ambrosiodmus lewisi belongs to the order Coleoptera, family Curculionidae, subfamily Scolytinae. It is a wood-boring insect commonly known as an ambrosia beetle, which spends the majority of its life cycle deep inside the woody tissues of host plants.

Host plants. This species is a polyphagous pest that targets a wide range of deciduous trees. Major hosts include various fruit-bearing species such as apple, pear, and peach, as well as forest trees like beech, oak, and chestnut. It poses a significant threat to both young orchards and stressed mature trees.

Biology and life cycle. The life cycle of the beetle is symbiotic with specific fungi. Female beetles bore galleries into the wood, where they cultivate these fungi to serve as food for their developing larvae. The larvae feed on the fungal mycelium rather than the wood itself. Depending on climate conditions, the insect can complete its generation cycle within several months to a full year.

Damage and pest impact. The primary damage is caused by the construction of extensive gallery systems within the wood, which disrupt the vascular system and sap flow. Visible symptoms often include gumming or sap flow at entry points. Secondary infection by pathogens typically follows, leading to the rapid decline and eventual death of the affected trees, while wood quality significantly deteriorates.

Control measures. Due to the concealed nature of the pest, control is challenging. Integrated management strategies include:

• Prompt removal and destruction of heavily infested trees to reduce local population pressure.
• Implementing proper irrigation and fertilization to maintain overall tree health and vigor.
• Using pheromone traps for population monitoring and timing of management activities.
• Applying contact insecticides during peak beetle flight periods to prevent successful colonization of healthy trees.