ST. PAUL (AP) - "Parasitic flesh flies" sound pretty unpleasant, but Minnesotans may have them to thank for stopping a big outbreak of tent caterpillars this year.

Tent caterpillars hatch from cocoons in May and June to eat leaves from trees. In 2012, tent caterpillars defoliated 275,000 acres of trees in Minnesota. Last year they got 1.1 million acres. This year's hatch was expected to be worse.

But parasitic flesh flies lay their eggs in the caterpillars' cocoons, then the young flies eat the caterpillars over the winter.

Department of Natural Resources officials say it's too early to know for sure, but it seems the tent caterpillar hatch has already peaked.

This year's hatch of tent caterpillars has been spotty and light so far.