Training diagnostics and surveillance practitioners during a live response: Polyphagous Shot Hole Borer (PSHB) workshop

The Polyphagous Shot Hole Borer (PSHB), Euwallacea fornicates (Eichhoff, 1868), is a small beetle native to Southeast Asia. The beetle invades tree trunks, stems, and branches where it farms its symbiotic fungi, including Fusarium and Graphium species. The fungi grow in the galleries made by the beetle and serve as a food source for the beetle and its larvae, but are also pathogenic to the tree, killing the vascular tissue. Susceptible trees die within a few years due to dieback. PSHB is known to be highly invasive, attacking a large range of plant host species globally.

PSHB was first detected in 2021 in Perth, Western Australia (WA), where a Quarantine Area has been set to limit its spread in the state and across Australia. A long list of hosts has already been reported for WA. Since PSHB is a biosecurity threat for the eastern states and is currently under eradication in WA, the National Implementation Working Group (NIWG) and the Plant Surveillance Network Working Group (PSNWG) deemed a workshop to pass on valuable knowledge gained during this incursion as critical for both diagnostic and surveillance practitioners around the country.

The PSHB Workshop was held in Perth, 2 - 4 May 2023, guided by workshop demonstrators Kylie Ireland (surveillance), Melinda Moir (entomology), and Dominie Wright (pathology). The workshop served as the perfect opportunity to train 20 biosecurity personnel from surveillance, preparedness and response, and diagnostics backgrounds across Australia. Attendees learned how to:

• identify PSHB beetles
• identify affected trees
• isolate and identify Fusarium AF-18 and Graphium euwallaceae from both the beetle and the tree hosts.

Participants left with handouts (physical and electronic) on the morphology of PHSB and the associated Fusarium spp., along with preserved specimens of PSHB, to take back to their organisations.

Feedback from all respondents mentioned that the workshop was a valuable learning experience, stating that the in-person and hands-on training made the workshop value for money and time. One participant mentioned that there is ‘no substitute for seeing a pest with your own eyes and the workshop has increased our likelihood of early detection in the event of PSHB arriving in SA’, with another commenting that ‘...it was discussing ideas with a room of diagnosticians that rarely get a chance to compare notes and exploring some of the trials and tribulations of the WA PSHB response that were the most valuable parts of the trip by far’.

Many participants communicated their increased confidence in surveying for and identifying PSHB beetles, the vectored fungi, and/or in-field symptoms since attending the workshop. Participants also left with a better understanding of the potential threats that a PSHB incursion could have on the other states/territories of Australia.

The training workshop and member’s attendance were supported through the National Plant Biosecurity Diagnostic and Surveillance Professional Development and Protocols Projects, coordinated and delivered by Plant Health Australia and funded by the Department of Agriculture, Fisheries and Forestry. The objectives of the project are to enhance and strengthen Australia’s diagnostic capacity and capability to identify priority plant pests that impact on plant industries, environment, and the community.

For updates on PSHB in WA, please visit: https://www.agric.wa.gov.au/borer.

Image from: https://www.agric.wa.gov.au/sites/gateway/files/PSHB%20Factsheet.pdf