Minnesota now has several dogs in the fight against the emerald ash borer.

In a first-in-the-nation strategy to contain the pest, state agriculture officials have hired dogs to sniff out ash borers and their larvae before they might be carried out of infested areas.

Four dogs, already trained to find endangered species of plants and animals, other invasive pests and even human remains, have been training in Minnesota since April to detect both ash wood and ash borers.

At a demonstration Tuesday in Arden Hills, two of them -- Denali, a shaggy, 10-year-old German shepherd from Reno, Nev., and Wicket, an 8-year-old Lab from Three Forks, Mont. -- bounded over a tangled pile of waste brush and a 5-foot-tall mulch pile before proudly discovering their prey, each in about two minutes.

"We smell parts per thousand. Dogs smell parts per trillion," said Aimee Hurt, co-founder and director of operations for Working Dogs for Conservation, based in Three Forks, whose eight dogs have tracked Chinese bush clover in Iowa, rosy wolfsnail in Hawaii and brown tree snakes in Guam. "They're a magic combination of really good sensing abilities with an interest in communicating with us."

Hurt's group and Wilderness Finders Inc., of Reno, are working with Minnesota under a $370,000 two-year federal grant. Geir Friisoe, the state plant protection director, said he believes the program will pay for itself once the dogs are trained and working regularly in Minnesota.

Emerald ash borer was first detected in Minnesota three years ago to the day Wednesday in St. Paul. A year later, it was detected in Minneapolis. As a result, ash wood is prohibited from being hauled outside of Ramsey and Hennepin counties -- as well as Houston and Winona counties, where the bug has also been found -- without an agreement with the state agriculture department and an inspection.

Dogs would fortify such inspections. During Tuesday's demonstration at the Ramsey County compost site, Wicket found two small ash logs in a large pile of mixed tree waste, and Denali homed in on three bags of infested mulch that had been buried in the 5-foot-tall mulch pile. The dogs in training will begin more "real-life" situations in July, checking ash that's been freshly removed from public and private land and brought to waste sites, Hurt said.

Emerald ash borer is believed to have arrived in the United States in the Detroit area in the 1990s, although it was not identified until 2002. It has since been found in 15 states and two Canadian provinces, and has killed millions of ash trees, which in North America have no resistance to the bug.

"The fact that we've gone to these lengths indicates this is a really serious pest we want to keep in place," said Mark Abrahamson, the state's lead ash borer monitor.

"Not every bug that comes along is going to be worth an effort like this."

Bill McAuliffe • 612-673-7646