Black Cutworm Moths Just Keep Coming

Much of the corn that was planted in the last couple of weeks is emerging or has recently emerged. One pest that can impact early corn stands is black cutworm. Black cutworm moth catches in many of Purdue cooperator’s pheromone traps continue to be quite impressive (see “Black Cutworm Adult Pheromone Trap Report” third link below). The timing of intensive moth captures, 9 or more moths caught over a 2-night period, over the past several weeks and subsequent larval development may challenge corn that is delayed in emergence or yet to be planted. This will be especially true for fields with abundant broadleaf weeds (esp. chickweed), if producers’ weed control activities are delayed or replanting is necessary because of low temperatures in the coming days (May 8-10).


The picture above is from Purdue Pest & Crop Newsletter, showing the larvae stages of black cutworm. The larger stages can cut plants while the small larvae punch holes in the leaves). Remember that black cutworm enters your fields by the moth that lays eggs there. When the eggs hatch, the larvae will often live at or near the soil surface and feed on seedling plants. Moths often favor fields with more plant cover (i.e. no till fields with winter annuals or unsprayed fields, cover crop fields) and earlier planted corn with more growth.Luckily, insecticides like Fastac are viable options for controlling this pest. Consider adding an insecticide to your early POST herbicide applicaitons or making a separate application if feeding by black cutworms exceeds 4-6% of corn plants or 20% of soybean plants.
To learn more about black cutworm, visit the links here:
https://extension2.missouri.edu/g7112
https://ipm.missouri.edu/pestMonitoring/bcw/identification.cfm

https://extension.entm.purdue.edu/newsletters/pestandcrop/article/black-cutworm-moths-just-keep-coming/

https://extension.entm.purdue.edu/newsletters/pestandcrop/article/2020-black-cutworm-pheromone-trap-report-5/