MITCHELL, S.D. (AP) - A beetle that's a quarter-inch long and originally from China could help control salt cedar, a plant that crowds out competition and is labeled a noxious week in South Dakota.

The state Department of Agriculture has introduced the yellow striped Chinese Diorhabda beetle in recent years to stop the plant, which can grow as a shrub or tree and covers about 6,500 acres in the state.

It crowds out native plants and wildlife habitat by growing 25 feet tall. The tree brings salt up from the soil and exudes it from the leaves, leaving salt crystal on the ground that prevents germination by other plants. Its roots can be 30 feet deep and suck up to 200 gallons of water per day.

"I'd say it's a concern - a major concern," said Mike Stenson, a weed management technician with the Department of Agriculture. "If we ignore it, it will be a major problem."

Members of the Missouri River Association of States and Tribes included it on their agenda during a recent meeting in Pierre.

Stenson said Diorhabda beetles keep salt cedar in check naturally in China, and it's hoped the bugs can do the same here.

"That's the way all biological control works," Stenson said. "We have invasive species from other places, and they don't have any of their natural predators. Basically, the way it works is scientists go back to the home range, find a predator, and bring it over here."

A mature plant can produce 600,000 seeds, which can be carried by the wind and water. The seeds can germinate while afloat or once they hit moist soil. On the Missouri River reservoirs Lake Oahe and Lake Sharpe, the seeds germinate while on the river surface and put down roots once they hit land.

"Every major drainage in western South Dakota, we've covered and have found salt cedar," Stenson said. "And we're starting to see it more in eastern South Dakota popping up around the cattail sloughs, which is kind of discouraging for us, but we are seeing it pretty much everywhere we look."

It's impossible to pull the plants because of the deep root system, he said.

Federal funding of $25,000 is available to spray for salt cedar in eight counties bordering Lake Oahe. Herbicides are effective and fast-acting but also are more expensive and labor intensive.