MINNEAPOLIS (AP) - Forest tent caterpillars are busting out in Minnesota but experts say this year's defoliation is not yet "the big one."

Department of Natural Resources forest health specialist Jana Albers says it's leading up to a bigger outbreak in a few years.

The DNR is seeing an uptick in the forest tent caterpillar population in Minnesota's northern counties this year. In west-central counties, the insects have been in outbreak mode for several years.

The caterpillars develop in cycles over the course of decades or more. They set a record in 2002-03, stripping 7.5 million acres of trees of their leaves in central and northern Minnesota. Fortunately, affected trees almost always recover.

The DNR will begin aerial surveys next week to track the caterpillars and other pests.

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