ANDREA SEABROOK, host:
Invasive plants are taking over some areas of the Western United States, crowding out native plants and changing ecosystems. Nearly every land management agency has an invasive species control program, and the folks who run them see themselves as warriors of sorts, protecting their land from invaders.
NPR's Jeff Brady spent the day with a Bureau of Land Management weed crew in Grand Junction, Colorado. He sent this report.
JEFF BRADY: The three-person crew is responsible for an area nearly the size of Delaware. Typically, they use an all-terrain vehicle to get around, but sometimes it makes more sense to travel by water.
(Soundbite of an air pump)
BRADY: A 16-foot yellow raft needs a little more air before the crew starts to motor down the river. Sparky Taber is steering. The nickname was earned during his years as a wildland firefighter.
Mr. SPARKY TABER (Weed Crew, Bureau of Land Management): We're going to park here in just a second. Got to get below this little rapid here.
BRADY: Taber aims the raft at the crew's first target, an 8,000-square-foot patch of Russian knapweed.
Ms. KACEY CONWAY (Weed Crew, Bureau of Land Management): This is a plant that terrorizes the West.
(Soundbite of laughter)
BRADY: Kacey Conway says it crowds out native grasses and bushes and spreads into pasture, destroying valuable fodder. Conway preps for the assault while Taber mixes herbicide with soap, which makes it stick to the plants, and blue dye, so they know where they've sprayed.
In her blue coveralls, Kacey Conway tromps through waist-high weed, with a long hose connected to the tank of herbicide back on the raft. She stops and takes aim.
(Soundbite of spraying)
BRADY: This is a good time of year to spray Russian knapweed, says Conway. It's preparing for winter by sending nutrients down to the roots. Now, she says, it'll take the herbicide with it.
Ms. CONWAY: This plant puts out its toxin in its roots - from its roots. And this toxin, called an allelopathic toxin, which means that it doesn't allow other plants to grow where it grows.
BRADY: Surveying the now blue-tinted patch of weeds, Conway takes a GPS reading. She and her spray partner have logged more than 3,000 sites like this over the past six months.
After cleaning up, the crew is off to its next battle site. This time, the target is tamarisk, also known as salt cedar. These bushes grow into tall thickets that crowd out native willows and cottonwoods. And they're thirsty. One tamarisk can use 100 gallons of water or more in a day; it's a problem in the arid West, especially during drought years.
It's expensive to take tamarisk out by hand, so the crew is relying on small beetles.
Mr. DAN BEAN (Colorado Department of Agriculture, Insectory Division): They're sometimes pretty hard to see. They blend in better than you might think.
BRADY: Dan Bean is with the Colorado Department of Agriculture's Insectory. Although the beetles are non-native, they'd rather starve than eat anything but tamarisk. The crew is searching for beetles released a few months back.
Mr. BEAN: And the standard rule is anybody that finds an adult gets a six pack of beer.
BRADY: After about 15 minutes, Sparky Taber spots one.
Mr. TABER: All right, Dan. There's an adult right there. See the stripes on - oop.
Mr. BEAN: Now he's going to fly away.
Mr. TABER: Don't. Don't leave yet. Ohhh.
BRADY: There's evidence the bugs have been chewing on the tamarisk. Bean hopes the beetles will eat until there are no leaves left.
It's getting late, almost dinnertime, and the crew heads home for the day. Tomorrow they'll be back. There are several lifetimes of work out here, maybe just a little less if those beetles take hold.
Jeff Brady, NPR News, Denver.