Polyphagous Shot Hole Borer, a Global Threat to Forest Plantations, Green Infrastructure, and Biodiversity: Status, Challenges, and Solutions

Global trade and climate change are accelerating the spread and impacts of invasive forest pests worldwide. The Polyphagous Shot Hole Borer (Euwallacea fornicatus) is among the most destructive invasive ambrosia beetles, attacking approximately 680 woody plant species across five continents and causing substantial ecological and economic losses. This review synthesizes the current knowledge of PSHB taxonomy, biology, fungal symbiosis, host range, invasion history, surveillance and management. Evidence indicates that eradication is rarely feasible once populations become established, while existing chemical and biological control measures remain of limited effectiveness, making early detection and rapid response essential. This review highlights major knowledge gaps in invasion biology, host susceptibility, fungal interactions and chemical ecology, and identifies research priorities to improve surveillance, risk prediction and integrated management. Advancing these areas will strengthen global biosecurity and enhance protection of forests, urban trees and commercial orchards.