On hot days, bertha armyworms take shelter low in the canopy or on the ground under leaf litter. This is not a good time to scout or spray. Bertha armyworms feed more actively on cooler days and in evenings. This is the time to spray. When scouting, include all worms larger than half an inch long in threshold counts. Smaller larvae may succumb to natural predators or diseases prior to contributing to significant feeding damage. However, if significant numbers of smaller larvae are observed, revisit the field regularly to monitor populations. Click here for scouting tips from last week’s Canola Watch.
