LA GRANDE -- A storm of 2-inch-long grasshoppers swept across

in southeastern Oregon's high desert last summer -- turning roads slippery, crunchy and "kind of gross" on their way to devouring 7,000 acres of grass intended as spring forage for the cattle

.

"Most people slowed down out of curiosity and awe" as clouds of grasshoppers carpeted Oregon 205 that passes through Roaring Springs, said ranch resident Elaine Davies.

The onslaught may be a mere prelude to a grasshopper invasion of near-mythic proportions predicted this summer in

and across the American West.

Hungry grasshoppers are starting to hatch in Arizona and New Mexico and could make 2010 the worst grasshopper year since the mid-1980s -- consuming huge swaths of grasslands and crops, said U.S. Department of Agriculture expert Charles Brown. The anticipated glut results from natural population cycles and widespread drought conditions that grasshoppers thrive under.

, said Brown, who oversees the USDA's national grasshopper suppression program.

Of several hundred types of grasshoppers, ranchers and farmers throughout the West are likely to encounter up to 15 hungry "pest species" this summer, he said. In Oregon, a clear-winged grasshopper called

are the culprits.

Grasshoppers munched their way across tens of thousands of acres of Harney County in 2009, and this summer's devastation could double to 140,000 acres in the county, entomologists said. Grasshopper activity probably will be centered on and around the million-acre-plus Roaring Springs Ranch south of Frenchglen,

itself and ranchland north of the 187,000-acre

.

Outbreaks also are possible in drought-stricken Klamath and Lake counties this summer or next year, said entomologist Helmuth Rogg of the Oregon Department of Agriculture in Salem.

The hatch will spread into Oregon and other northern states in the coming weeks as chilly spring temperatures give way to warmer weather. Grasshopper egg beds typically occupy dry, south-facing slopes just far enough underground to escape fast-moving range fires, biologists say.

The grasshopper plague probably will hit its stride in August as summertime heat parches Western croplands and open ranges. Grasshoppers often consume their own weight in forage and crops in a day. Eight grasshoppers per square yard are enough to cause economic damage, Rogg said.

"They are the lawnmower of the prairie," he said. "The biggest biomass consumers on the North American prairie are grasshoppers -- not cattle, not bison, not antelope."

The pests can reduce rangeland forage by 80 percent in areas as large as 2,000 square miles, Brown said.

The most effective control is the pesticide Dimilin , a growth regulator that kills young grasshoppers just after the hatch, he said.

The federal government will pay all costs for pesticide applications on federal lands, 50 percent on state lands and a third on privately owned lands. Some landowners, including the owners of Roaring Springs, opt to pay the costs themselves.

"When it comes time to cost-share, there is too much red tape for me," said Roaring Springs foreman Stacy Davies.

He and a crew of buckaroos will begin searching for egg beds on horseback, ATVs and on foot as soon as the ranch gets some warmer weather, he said. Roaring Springs' elevation is at 4,600 feet and the mercury tumbled into the low 20s several times in the past week, he said.

Treating the ranch's egg beds with Dimilin probably will cost $4,000 and save 20,000 acres of grass, Davies said. That works better than battling clouds of mature hoppers later in the season with Malathion, a less environmentally friendly pesticide, that could cost $25,000 and leave the grass at greater risk, he said.

Successful Dimilin treatments in Oregon reduced the grasshopper infestation from 1 million acres in 2008 to 150,000 acres last year, Rogg said.

"All the other states went the other way" -- and watched grasshopper populations multiply because they didn't find and treat egg beds, he said. "They are all going to look forward to big outbreaks."

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