Canola Insect Trapping Update | Northern Canola Growers Association

Pheromone traps for bertha armyworm and diamondback moth are being monitored by IPM scouts and insect trappers through the IPM Crop Survey Program in 16 counties of North Dakota and 1 county in Minnesota. So far, trap counts for bertha armyworm are low (<10 cumulative moths per trap per week) at all trap sites. For diamondback moth, traps counts are low in most canola production areas, but increasing in the north central canola production area. Scouting for diamondback moth is recommended in these areas with high weekly trap catches of over 100 moths per trap per week.

Scouting Tips for Diamondback moth: The newly hatched larva is light green and turns a darker green as it matures. Mature larvae are about ½ inch long. Larval feeding injury causes uneven maturity, aborted flowers, defoliation in leaves and direct feeding on pods. Critical scouting periods are during early flowering to mid-pod formation. Scout for larvae in the field by pulling all plants from a 1-square-foot area. Beat collected plants onto a clean surface or into a white bucket and then count the number of larvae dislodged from plants. Larvae often will dangle from canola plants on a silk thread. Repeat this procedure in at least five locations in the field to obtain an average of the number of larvae per square foot.

We will continue to report weekly trapping results for canola insects on the IPM website and the NDSU Extension Crop & Pest Report. Thanks to Northern Canola Growers Association and the UDSA NIFA CPPM EIP for support.

9 CPR July 7 2023 Final.pdf (ndsu.edu)