Ag officials plan more spraying for gypsy moths

Adult gypsy moths
The adult female is an off-white color, and cannot fly. The adult male is dark brown with markings.
Photo courtesy of Purdue University

Minnesota agriculture officials are planning to treat more than 700 acres near Lake Superior's North Shore for gypsy moths.

Officials will use a combination of treatments including the pesticide BTK and a chemical that disrupts the moths, making it difficult to find a mate.

Lucia Hunt, with the Minnesota Department of Agriculture, said gypsy moths have been found near the shore several seasons in a row, but their numbers spiked last year.

"We found a lot more insects than we did the years prior," Hunt said. "That prompted us to really take an aggressive look at treatment and management."

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Gypsy moth larva
The gypsy moth larvae do the damage by eating foliage off trees.
Photo courtesy of USDA Forest Service

Hunt said officials need public cooperation to keep the pest at bay.

Once established, the moths could defoliate large tracts of their favorite trees, which include aspen and birch.

"The public needs to know that it is a real destructive invasive species, and if we allow it to get a foothold on the north shore, we could be looking at some severe defoliation within the next five to 10 years," she said.

Officials aren't sure yet whether the bugs are reproducing locally, or whether they continue to drift in from infected regions like Upper Michigan.

Public meetings are planned in Two Harbors on Wednesday, and Silver Bay and Grand Marais on Thursday to explain this year's treatment plans.