OMAFRA: Watch for black cutworm in corn and soybean crops
By Top Crop Manager
Corn and soybean growers in Ontario are advised to be on the lookout for black cutworm larvae. Tracey Baute, field crop entomologist with the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), says agronomists and growers have reported cutting in the two crops. Black cutworm cutting in soybean is unusual, but two fields in the Niagara region have seen significant stand loss.
Fields not treated with an insecticide seed treatment or planted with a Bt hybrid containing Cry1F or Vip3A should be scouted every three to four days for the next few weeks. Factors that increase field risk include those with pre-plant annual weeds (eg. chickweed, mustards, volunteer wheat, lamb’s-quarters, velvetleaf etc.), cover crops or no-till/reduced till.
Look for pin-holes in leaves and wilting or cut plants above or below ground. Dig around damaged plants to search for cutworms in the soil, where they hide during the day. Larvae larger than 2.5 cm are too big to control, though some fields may have a range of sizes. |READ MORE