HUTCHINSON (AP) -- Kansas Livestock Commissioner George Teagarden calls them an invasive species -- nuisances that root up crops and pastures like a rototiller.

Yet as efforts continue to eradicate feral hogs from the Kansas plains, Teagarden says there is evidence that some people are still illegally transporting feral hogs into the state, possibly as a way to bolster Kansas' hunting industry.

"We are sure they are being transported into the state and transported around the state," said Teagarden, who runs the Kansas Animal Health Department. "Feral swine aren't good for the state. There are a few people who want to be able to hunt them, but the destruction they cause outweighs what we'd gain."

Hunters shell out a few hundred bucks a day to hunt wild hogs in Texas. But in Kansas, officials want to rid the state of the grunting and rooting animal that rips up pastures and is nearly as prolific as a rabbit.

The Kansas Legislature passed a law in 2006 banning feral hog hunting. Since then, Teagarden's agency, with help from the U.S. Department of Agriculture's Wildlife Services, has been killing feral hogs from the air across south-central and eastern Kansas. They also trap them during the year in hopes of someday ridding them from the state completely.

The annual helicopter hunt got under way Tuesday along the Oklahoma border, starting first in Elkhart, then moving to Barber, Cowley and Douglas counties, said John Johnson, a wildlife biologist with the USDA agency who heads up the aerial team.

"We're making a tremendous dent," Johnson said. "But our biggest fear is that these hogs get dumped out and we don't hear about it for a year."

With just himself and one other person working full time to curb the problem, "We can't be everywhere," Johnson said.

When the project started, officials estimated Kansas had 2,000 hogs causing $200,000 to $300,000 in damage a year to field crops and pastures, as well the spread of disease. Last year, Johnson's group took more than 450 hogs from Kansas, with about 230 from the aerial project, he said.

He estimates about 1,000 to 1,500 feral hogs still reside in the state. A 15 percent slash to the budget, however, will cut back on the eradication program. Johnson said the cuts would mean going to some counties every other year rather than yearly.

The first three years of the program have cost about $450,000, according to the animal health department.

Efforts, however, have been successful. Aerial flights over Douglas and Cowley counties are more a "maintenance flight," Johnson said.

"We probably won't kill any pigs there," he said.

In Morton County, most of the pigs are on the Colorado side, he said. The agency is working with the Colorado Division of Wildlife to eradicate the pigs.

Johnson said his team isn't flying in the worst area of the state, Bourbon County in southeast Kansas.

"It's the only place in the state we don't have 100 percent landowner cooperation," he said. "We're still doing a lot of groundwork over there."

As for illegal wild hog dumping, Johnson said there are a couple of cases being investigated. No charges have been filed.

"Mainly, we need to improve and work on the enforcement of the laws we have," he said.