Thousands, maybe millions, of Mormon crickets hide in the underbrush quiet as a sigh south of Holbrook Summit.
They're waiting for a cloud to move away from the sun. When it does, a horde scampers across a Bureau of Land Management road - a brown wave cutting a swath more than three-tenths of a mile wide.It happens every year as bands of crickets migrate 25 to 50 miles across southeast Idaho.
And if the weather conditions are right, as they are this year - warm and dry - the crickets could wander on to the streets of downtown Malad. Or maybe Pocatello, said Matt Rendace, BLM range conservationist for the Deep Creek Resource Area.
Idaho, especially the Malad area, has the largest concentration of Mormon crickets in the country. And this year is the worst, Rendace said.
Three-quarters of an inch in size now, the crickets will grow to 11/2 inches, resembling black bullets with feet. Rendace said their population density can reach 75 crickets per square yard. In 1938, the crickets infested more than 19 million acres covering 11 states.
"No one knows why they migrate or where they're going," he said. They hatch at high elevations as soon as the ground temperature reaches 40 degrees, then work their way down to lower climes.
Legend has it that the crickets, which Indians ate as a delicacy as far back as 2200 B.C., beset a band of Mormons in the Utah territory.
The besieged band prayed for salvation and were saved by seagulls that swooped down to eat the crickets. Thus, the pests were named Mormon crickets.
Weather seems to be the only thing that hampers them. Cold, wet conditions stymie their growth and reproduction. The crickets don't have many natural predators other than gulls, rodents, hawks, crows and digger wasps.
Rendace said the cricket is an efficient little bug.
"They eat just about anything, including each other," he said.
One cricket will consume up to 38 pounds of forage. Mormon crickets feed on sagebrush, but they relish cultivated plants, devouring wheat, barley, alfalfa and garden vegetables.
Traveling up to a mile a day when the sky is clear and temperatures above 65 degrees, the crickets reach their destination sometime in July. At that time, they mate and die. Prior to dying, the female lays as many as 160 eggs, up to 35 a day, in bare ground. As soon as she deposits an egg in the soil, she covers it, and the egg lies dormant until the next spring.
Rendace said that it's impossible for the BLM to handle the wandering bands. BLM officials have tried biological control, using a fungus that kills the crickets when they eat it. Or dropping oats rolled in poison along a migration route.
In the past, when it got bad enough, officials sprayed from the air.
But what works one day is insignificant the next, Rendace said.
"It's impossible to guess which way the critters will go," he said.