PSHB Threat in Western Australia: From Eradication Efforts to Research Breakthrough

The polyphagous shot-hole borer (PSHB), identified as Euwallacea fornicatus, poses a significant threat to Western Australia's trees. First detected in Fremantle in 2021, this invasive beetle has since impacted numerous tree species, leading to severe damage and challenging initial eradication attempts.

Initial eradication efforts have not been successful.

Understanding the PSHB Threat

PSHB is a beetle native to Southeast Asia, distinguished by its symbiotic relationship with a fungus, Fusarium euwallacea. The beetle's destructive method involves tunneling into trees, where it cultivates this fungus as a primary food source for itself and its larvae. This fungal growth critically impedes the flow of water and nutrients within the host tree, often resulting in severe damage or eventual tree death.

Government Shifts Focus: From Eradication to Management

Following its initial detection, the Western Australian Government launched a multi-million dollar biosecurity response. This comprehensive effort included the establishment of quarantine zones and the removal of thousands of infested trees from both public and private properties.

However, in 2025, the WA Government announced a critical shift in its strategy.

Eradication of PSHB was no longer considered feasible.

This decision was influenced by several factors, including the inherent difficulty in detecting the beetles, their rapid reproduction rate, and the absence of effective pesticides. Consequently, the focus has pivoted towards the long-term management of this pervasive pest.

Breakthrough in Research: A New Path Forward

A significant development emerged in January 2026, when a research team from Murdoch University, comprising PhD student Md Shahidul Islam Khan and Associate Professors Wei Xu and Rob Emery, announced a pivotal achievement: the successful establishment of the first PSHB lab colony.

The team meticulously collected beetles from infested locations and replicated their natural environmental conditions within a laboratory setting. Under these controlled circumstances, the beetles exhibited typical behaviors, including tunneling and the successful cultivation of their symbiotic Fusarium fungus.

This groundbreaking development is set to revolutionize PSHB research. Establishing a stable lab colony now enables scientists to thoroughly study the borer's life cycle under controlled conditions, offering invaluable insights into its behavior and responses to various chemical stimuli.

Mr. Khan highlighted that "a stable colony facilitates the rapid and safe screening of potential attractants, repellents, and environmentally friendly control methods crucial for early detection."

Dr. Xu further underscored the importance of this work, stating, "This project represents a significant advancement in protecting Western Australia's landscapes from PSHB damage, by developing targeted tools based on a deeper understanding of the pest."