BOISE, Idaho (AP) — Progress is being made eradicating a microscopic pest that has been threatening Idaho's $900 million potato industry the last decade, federal officials say.

The U.S. Department of Agriculture said viable potato cyst nematodes can no longer be detected in three additional fields. The agency on Friday released the first quarter report for 2017 on the Pale Cyst Nematode Eradication Program that said 20 of the 27 infected fields have now reached that step in a lengthy process to return to production.

About 9,300 acres (3,700 hectares) are being regulated because of the pest in...