Native budworm was one of the biggest pests to impact Western Australian crops this year, and it is important to keep monitoring paddocks for caterpillars.
That was the advice from Department of Primary Industries and Regional Development (DPIRD) crop protection senior research scientist, Svetlana Micic, speaking on a DPIRD PestFacts WA Webinar last week.
She said there had been an early onset of native budworm moth flights in June, when DPIRD started its pheromone trapping program.
"We are finding the moths are coming into crops earlier and earlier each year, especially in the northern Wheatbelt," Ms Micic said.
"We have been checking our traps every two weeks and finding moths even up to last week - with 400 at one Katanning location."
Ms Micic said the budworm moths preferred to lay eggs on green material, so late-sown crops were the most at risk.
She said desiccated and swathed canola was not immune to damage from native budworm.
Ms Micic said crop monitoring had revealed native budworm caterpillars at sites right across WA's agricultural region.
"Our advice is to actively monitor and don't apply any sprays unless caterpillars are at threshold levels," she said.
"Threshold levels can be determined by sweep netting crops and then consulting the Crop Scout app.
"Just enter the counts per sweep and the app will determine if you need to spray."
Given recent warm conditions, Ms Micic said there was some evidence of green peach aphid, cabbage aphid and turnip aphid in crops in some areas.
She recommended growers keep a close watch on any aphid activity and treat crops if thresholds were reached.
"We expect to see an increase in aphid activity heading into the warmer months, but these should not be a real issue at this stage of the crop growth cycle," Ms Micic said.
She said DPIRD researchers were monitoring diamondback moth, and it seemed any significant numbers were currently restricted to the Esperance Port Zone.
"Fortunately, diamondback moth caterpillars have not ramped up above threshold levels for most areas, unlike last year when there were widespread outbreaks at this time of year," Ms Micic said.
"Once the crop starts to senesce, diamondback moth caterpillars don't have an effect on grain yields.
"So growers should be pretty safe stopping monitoring for this pest in podding canola crops at the grain fill stage."
When it comes to snails and slugs, Ms Micic said the advice was to check what activity was occurring, as levels now would be the same as those going into next season.
"Slugs and snails can survive the hot dry summer," she said.
"Red-legged earth mites can also survive over summer, and I would be particularly looking out for them in the central and northern parts of the agricultural zone in the next few weeks."
Ms Micic said ensuring good summer weed control would disrupt the lifecycle of many major crop pests and was good insurance going into season 2026.