Black Cutworm Return Dictates Scouting Fields to Determine Risk

Obermeyer on black cutworm

John Obermeyer PurdueWill Hoosier farmers again be dealing with black cutworm this year? A Purdue specialist can confirm the pest is back. John Obermeyer is an Integrated Pest Management Specialist who says the moths are migrating from the southwest.

“As in every year we monitor for black cutworm arrival into the state and just as every year they have arrived,” he told HAT. “Although not the largest numbers we’ve ever seen, monitoring now for 20 plus years, but there is certainly a significant number and at the time when they were coming in bigger numbers now their development is probably going to coincide well with especially some of that later planted corn that went in.”

Obermeyer says the moths are definitely attracted to certain fields, particularly those with lots of weeds, “especially chickweeds and dandelions and henbits, and you name it. And of course the producers do the best they can to burn all that down or till it before crop emergence, but sometimes the cutworms have already established in there and they’ve already started to develop and just as the weeds are dying back the corn crop is emerging and that’s when the bad things start to happen.”

To prevent those bad things from happening scouting fields is a must. And it’s best to scout fields even where Bt corn is planted and fields with seed applied insecticide. Those fields are not immune even with that built in protection.

“When we have heavy infestations sometimes it’s just not enough and it’s a great idea for producers to get out and check fields and if necessary apply a foliar insecticide if the damage is over 3-5 percent leaf feeding and cutting as well.”

In what he calls high risk situations, Obermeyer says not even the higher rates of seed applied insecticide are enough to keep damage at bay. Learn more in the Purdue Pest and Crop issue #7.

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