Spring has many great things to offer for Midwesterners. Some of the season’s traits are appreciated, like the warmer winds, fresh blooms and the promise of another chance for farmers to do what they love to do for another year. Other gifts aren’t such keepers, like a bit too much moisture and the return of many invasive pests that can take yield potential away from fields as soon as a plant breaks through.
One of those critters is the black cutworm, which is beginning to make its way into Ohio now.
“Black cutworm is considered an invasive species for our part of the country because, as moths, they fly our way from the central part of the U.S. every spring,” said Ron Hammond, Ohio State University’s College of Food, Agricultural, and Environmental Science entomologist. “When it warms up fronts bring winds from the south and we are starting to see moths in Ohio this month.”
Black cutworms tend to be attracted to various weeds, mostly winter annuals and, to be more specific, chickweed. As soon as they find their place in a field, they begin laying their eggs. The threat is a little lower if a field has been conventionally plowed when weeds aren’t as evident.
“Where we usually find most of the females is in a no-till field where weed control has been an issue,” Hammond said. “The issue we may run into this year is that the burndown application won’t have the time to do its job fully by the time the corn plant starts to pop up, giving the black cutworm a new leaf to feed on.”
As with any pest control, the first step is a literal one — into the field.
“Farmers can look for cutworms under dirt clods, on plant residue or one to two inches deep in the ground,” said Bill Mullen, director of agronomic services with Seed Consultants. “Make sure and look at five different areas of the field. Look for two or more cutworms per 100 plants throughout the field.”
Mullen suggests scouting for cutworms as soon as the corn emerges and continuing to routinely scout two times per week until the plants are 18 inches high, recording the number of plants that are cut or wilted or show signs of leaf feeding. It is better to scout earlier in the day because these pests feed overnight.
Of course, today’s seed technology includes insecticides and the cutworm is listed on the side of the bag, but how effective has this technology been?
“Cruiser, Poncho and Votivo are the most effective pre-treatments because they are in the plant,” Mullen said. “We know black cutworm will eat some plants, but that is just the nature of the beast. Usually with a pre-treated seed we will have a much greater chance of control than working with an insecticide.”
A generally warmer climate is one of the main reasons for concern about larger infestations of invasive pests. Experts say that, as the warmer weather moves into northern parts of the country, problems like black cutworm may not just move into Ohio when the spring winds begins to blow, they may over winter and start their migration from this area too.