DPIRD research scientist Christiaan Valentine and Mingenew Irwin Group project officer Jacqui Meares instal pitfall traps at a property near Dongara. Photo: DPIRD

A MYSTERIOUS weevil damaging crops in Western Australia’s Mid West will be the focus of a new project seeking to identify the pest and find out its distribution.

Dubbed the Dongara weevil, it was first reported in a canola crop on a property east of Dongara in 2013.

Local growers have since reported the tiny black weevil infesting canola and coriander crops in the district and adjacent Mingenew area.

In a project with co-investment from the Grains Research and Development Corporation, WA’s  Department of Primary Industries and Regional Development, Murdoch University,and the Mingenew Irwin Group have joined forces to find, describe or classify the weevil.

DPIRD research scientist Dustin Severtson said the project also aimed to expand the understanding of its distribution in WA and examine factors influencing the incidence and severity of crop damage caused by this species.

“An understanding of the host and environmental preferences, along with the taxonomic classification of the pest, is important for the development of tools and information to correctly identify the pest,” Dr Severtson said.

“This information will be pivotal to assist with the development of effective management strategies for this unidentified crop pest.”

The Dongara weevil. Photo: Dustin Severtson

Throughout the 2023 and 2024 seasons, surveillance will include many paddocks sampled during the season via pitfall traps within a 50km radius of known Dongara weevil sites.

“That surveillance should provide some preliminary observations of the soil type and crop hosts, crop/plant damage incidence and severity, and paddock histories.”

Mingenew Irwin Group project officer Jacqui Meares said weevil surveys in the area would help to understand its distribution and which farmers were potentially at risk of crop loss.

“This information will assist landholders in determining mitigation measures for future seasons,” Ms Meares said.

A taxonomic species description will be conducted by DPIRD, while Murdoch University will lead
the molecular analysis.

GRDC crop protection manager west Georgia Megirian said project results would be pivotal to
better inform possible future initiatives of managing this unidentified crop pest.

“This project represents a collaborative effort across various industries to gather knowledge on the
Dongara weevil, prompted by valuable feedback from local growers in the area,” Ms Megirian said.