Black cutworm numbers are high. There continue to be reports of high catch numbers of black cutworm (BCW) moths in pheromone traps throughout early May in the northeast. Early scouting of corn by WNYCMA staff confirm these warnings, as the larvae are around and actively feeding. Although cutworm can be present in any field, not all are at the same risk. The following are traits of fields that are at highest risk and should receive the most attention from farmers and agronomists:
- Fields with a lot of trash, pack manure, winter annual weeds, or cover crops: As BCW moths arrive on the winds, they prefer to lay their eggs in fields where their offspring will have the best chance for success. High organic matter fields that are “dirty” with vegetation or trash are particularly susceptible.
- No-till or minimum-till fields: Mold-board plowing buries the eggs deeper and when the larvae hatch, fewer survive to feed on corn plants.
- Fields without a high rate of Poncho or Cruiser: One of the overlooked benefits of neonicotinoid seed treatments is that they suppress black cutworm. Although not foolproof, corn seed treated with the 500 or 1250 (0.5 to 1.25 mg/kernel) rates often see less severe feeding.
- Fields without the Bt trait for BCW: Many GMO hybrids have a gene that produces a Bt trait that protects the young seedling against BCW. Your corn seed may have that trait even if you didn’t specifically ask for it. For example, hybrids with the suffix SS, AMXT or VT3, among others, express the trait. If you are not sure about a hybrid, google “Handy Bt Trait Table 2022” for an extensive list.
- Fields without planter box insecticide: Force insecticide banded for rootworm control also helps to protect against black cutworm. Conversely, my experience has shown that In-furrow treatments of capture are not effective.
It will be especially important to scout for cutworms this year because of the seemingly high numbers of moths that have landed in the area. Responsive treatments of BCW with insecticides are highly effective, but it is important to catch the problem early, before stands are greatly reduced.