Those who noticed red gypsy moth traps in Nisswa and other communities this past fall should be happy to know that no moths were found locally.
"We are looking at the data to see if there are finds to treat next year," said Allen Sommerfeld, of the Minnesota Department of Agriculture. "In the Nisswa area there were no gypsy moths found, so there is no concern or worry about that."
Sommerfeld said the traps are a method of monitoring the spread of invasive species, in this case gypsy moths. There have been no reports of invasive moths in the local area. Nisswa and other parts of Crow Wing and Cass counties were chosen for trapping based on their distance from other known infestations.
"We know it's in the state and approaching the eastern part of the state from Wisconsin," Sommerfeld said. "This year we put out 21,000 traps, mostly on the eastern one-third of the state. People may have seen them (traps) in Nisswa or throughout Crow Wing County, Morrison County, Aitkin, Mille Lacs and down into Benton and Stearns county. There were some in Cass County as well. That was the western edge of our trapping area."
Gypsy moths are not native to Minnesota and, lacking predators, can rapidly reproduce with one female producing up to 1,000 eggs. They can quickly strip large sections of trees and shrubs to the point of killing them if left unchecked. The Department of Agriculture has two methods of controlling gypsy moths.
"We can replicate what the female's pheromone is. We treat an area, and that confuses the male gypsy moths so they can't find a mate. The population just dies out," Sommerfeld said. "Then there is another treatment where we use an organic insecticide. It's a naturally occurring bacterium that's in our soil that we already find in Minnesota. We use the bacterium and treat the tree canopies. That targets the moths in the caterpillar stage."
The gypsy moth is spread much like the emerald ash borer (which the Department of Agriculture monitors and traps with purple traps) in firewood. They are also transported like aquatic invasive species by hitching a ride on recreational equipment.
"When we see the infestations that we have to go in and treat, most of the time we see them pop up in new areas because people have brought them in unknowingly," Sommerfeld said. "They move firewood from Wisconsin into Minnesota or they had a camper sitting somewhere, not knowing gypsy moths have laid eggs somewhere, or any other outdoor equipment. That's where we see these infestations."