Mid-West canola growers should monitor for Dongara weevil
- Dongara
- Yardarino
- Mingenew
- Nangetty
- Mount Budd
The Dongara weevil was detected near Mingenew in early April in pitfall traps set by Technical officer Montana Bradley (Mingenew Irwin Group (MIG)), and east of Dongara by DPIRD research staff as part of the 2024 pitfall trapping program in the Geraldton port zone.
Mid-west growers are reminded that Dongara weevil is known to inhabit certain clay soils in the Dongara and Mingenew region. The weevils can cause extensive damage to emerging canola by chewing on the hypocotyl at or just below the soil surface.
Dongara weevils are tiny, approximately 3 to 5 mm long, and appear dark brown to black in without prominent markings. They are smaller and darker than other weevils that commonly damage canola. Weevils can be very hard to find as they hide at the base of seedlings or in cracks in the soil during the day and are active at night. Placing pitfall traps into the ground can be an effective way to find weevils.
Dongara weevils have survived high-end rates of insecticides used for common pests of canola, including other weevils. Preliminary laboratory tolerance testing has shown chlorpyrifos to be effective on these weevils, bifenthrin to be somewhat effective, and alphacypermethrin to have low efficacy. As with other weevil pests, spraying in the evening when the weevils are active can be more effective.
The Dongara weevil surveillance program is part of a 2-year Grains Research and Development Corporation (GRDC) and DPIRD co-funded project. To read about the key findings to date, refer to the 2023 PestFacts WA Issue 21 article Dongara weevil investigation update.
Further Information
For more information on canola pest weevils visit DPIRD’s 2023 PestFacts WA Issue 3 Identifying weevils and Diagnosing weevils in canola pages.
If you are unsure of the type of weevil you have found in your crop, you can email the PestFacts WA team to request an identification by our entomologists.
For more information contact Research Scientist Andrew Phillips, Geraldton on +61 (08) 9956 8567.
Article author: Bec Severtson (DPIRD Northam).