Rocky Mountain Locust once swarmed in numbers unimaginable to modern farmers who use pesticides to protect their crops. According to the Fort Collins Museum Discovery Science Center, the 1874 swarm of Rocky Mountain Locust covered 198,000 square miles with an estimated 12.5 million insects. In the 1800s, farmers fought a seemingly endless battle with the locust, year after year, and many believed the locust would win. They gave up their dreams of farming and returned to their homes in the East.
Katie Bowell, Curator of Cultural Interpretation at the Fort Collins Museum & Discovery Science Center, "From July 20 to July 30 of 1874, a plague of locusts was recorded over the prairie that covered 198,000 square miles (approximately twice the size of my home state of Colorado) and contained at least 12.5 trillion individuals weighing approximately 27.5 million tons."
Ingalls describes her impression of the locust as they moved toward her family farm: "The cloud was grasshoppers.Their bodies hid the sun and made darkness. Their thin, large wings gleamed and glittered. The rasping whirring of their wings filled the whole air and they hit the ground and the house with the noise of a hailstorm..."
They lived on their land for five years, planting, harvesting, waiting for the day when they could finally file the title to your property. Then suddenly one a quiet, sunny morning there appeared a black cloud above their homes moving closer, faster, descending on their crops, streams, barns, animals, dreams, like a giant beast destroying every little plant that grew from every little seed that these men, their wives and children dropped by hand into the soil just months before.
Those families who were familiar with locust tied the openings of their clothing--shirt sleeves, pant legs--with string so the locust wouldn't climb inside, then rushed to cover their wells with anything they could find. Some tried to burn part of their crops, hoping the smoke would discourage the locust. It did not.
The families hid inside their mud houses. The sound was horrendous--crunching, crawling, scratching. When the creatures could not find something to eat, they began to eat each other. When the ground was bare, they moved on. For some settlers in the West, the loss was too much and they returned back home to their families in the East.
In 2010, when I first wrote this article, sources stated that all locusts are swarming grasshoppers in the Acrididae family. They become aggressive as their numbers grow and food sources become low.
However, it is now believed that the Rocky Mountain Locust, known as the M. spretus, is distinct. It once lived primarily in the Rocky Mountains, but spread into the prairies as its numbers grew, and continued to grow until clouds of locust filled the air for miles and miles. Between 1873 and 1877, locust swarms caused $200 million in crop damage in Colorado, Kansas, Minnesota, Missouri, and Nebraska. Imagine seeing a cloud of locust so large it covers the entire sky and turns day into night. As terrifying as a Bibilical plague.
Locust Plagues in History
Twenty-seven years after the largest locust swarm in recorded U.S. history, the Rocky Mountain Locust mysteriously disappeared. The last sighting of a Rocking Mountain Locust was in Southern Canada in 1902. In spite of the size of the 1874 swarm less than 300 specimens of the insects remain. It is, however, still possible to find Rocky Mountain Locust carcasses frozen in glaciers.
In an ironic twist, it is widely believed that these same farmers who were relentlessly tortured by plagues of locust eventually brought about the locust's demise by exposing their larvae while plowing their fields.
According to Katie Boswell: "DNA testing from museum specimens of the Rocky Mountain locust suggests that M. spretus was a distinct, and now extinct, species and the days of the locust on the scale of 12.5 trillion individuals are gone. If you do still want to find Rocky Mountain locusts, the best place to look (other than in a museum) is in a glacier. Throughout the west there are glaciers that have preserved the frozen bodies of locusts that once flew over them."
- Bennett, Chris. Western Farm Press. Accessed 2013.
- Bowell, Katie. The Rocky Mountain Locust. More to Explore. The Fort Collins Museum & Discovery Science Center. Accessed 2010.
- Lane, Rose Wilder. Let the Hurricane Roar. Harper & Row Publishers. New York: 1933.
- Wilder, Laura Ingalls. On the Banks of Plum Creek. Harper: 1937.
- Yoon, Carol Kaesuk. "Looking Back at the Days of the Locust." The New York Times. Posted April 23, 2002. Accessed 2010.