Cutworms, Northland gardeners wage war for this year's cropThe good news is that the variegated cutworms that showed up in the Northland for the first time this year aren’t expected to return.
By: Jana Hollingsworth, Duluth News Tribune
We told you they were coming, and now they’re here.
The good news is that the variegated cutworms that showed up in the Northland for the first time this year aren’t expected to return.
The cutworms are native to Minnesota, but are usually seen in the agricultural southern reaches of the state.
Lois and Doug Hoffbauer said they have caused more problems for certain produce on their Midway Township farm than the recent widespread flooding.
“This is the first year we have had them,” said Doug Hoffbauer, cutting open a worm-mottled tomato. “They do make an ugly-looking mess.”
The worms have left Swiss-cheese-style holes in the lower leaves of some of their tall tomato plants, and several tomatoes have also fallen victim.
The farmers, who grow everything from cucumbers to Christmas trees, have used organic bacteria spray called BT, plant coverings and cultivation to prevent the worms from eating their plants. They have been largely successful.
“We are really diligent” because of the large amount of food and flowers grown on the farm, said Lois Hoffbauer “We can’t just let things go.”
Cutworm moths invaded the Northland in May, laying eggs on siding and windows. Those eggs have hatched, and the worms are busy enjoying flowers, tomato plants and other greenery.
This type of cutworm doesn’t feed right on the ground, cutting stems off close to the soil line as other species do, said Jeff Hahn, an entomologist with the University of Minnesota Extension.
“This species will actually climb up and feed on the leaves and cause damage,” he said.
The worms are here this year because the adult moths flew in on air currents from the south, he said. “They get large flights and can get on air currents and get blown up here.
“Because you don’t typically see them, you probably won’t next year,” Hahn said. “It was the perfect storm of events that created so many and pushed them that far north. I wouldn’t expect this to be an ongoing problem.”
The small worms are close to being through the caterpillar stage, said Tom Kasper, supervisor of street and park maintenance for the city of Duluth.
He suggested using BT spray or going outdoors at night when the nocturnal worms are eating.
“Even raking soil around plants or pressing down with your foot can kill quite a few of them,” he said.
The worms, which aren’t hairy, are brown or black and have yellow diamond shapes toward the beginning of the body, Hahn said. He said picking them off plants and putting them in a soapy pail of water works, too.
“Catch them in the act,” Hahn said. “Caterpillars don’t move quickly.”
The Hoffbauers, who own Balsam Wreaths and head the Duluth Farmers Market, recommend that the average gardener use other methods before resorting to organic spray. The worms can build up a resistance to the spray, he said.
“Every year it’s a different bug,” Doug Hoffbauer said. “You have to be ready for them.”