Poplar nematode

Systematic position: Bursaphelenchus populi belongs to the phylum Nematoda, class Chromadorea, order Aphelenchida, and family Aphelenchoididae. It is a specialized migratory endoparasitic nematode that lives within the xylem of host trees.

Host plants: The primary hosts for this pest are members of the genus Populus (poplars). The nematode colonizes the wood tissues, causing structural and physiological damage to the host, which is particularly problematic in commercial poplar plantations.

Biology and life cycle: The life cycle is strongly associated with insect vectors, primarily wood-boring beetles (Coleoptera: Cerambycidae). The nematode uses these beetles for dispersal between trees. Once introduced into a host, the nematodes multiply rapidly within the wood, feeding on parenchyma cells and the fungal mycelium often present in stressed trees.

Damage and severity: Damage is characterized by the obstruction of water-conducting vessels, resulting in wilt symptoms, bark lesions, and the eventual dieback of branches or the whole tree. The economic impact includes mortality of trees, reduced timber value, and the loss of aesthetic value in urban landscapes.

Control measures: Management is complex due to the internal nature of the infestation.

• Removal and destruction of infested and symptomatic trees to reduce inoculum sources.
• Management of beetle vector populations through forest hygiene practices.
• Avoiding the movement of wood products from infested areas to prevent spread.
• Selection of resistant poplar clones for new plantations to minimize susceptibility.