In Wilder’s fourth book, “On the Banks of Plum Creek,” Laura describes in detail a large cloud that darkened the sky. The family assumed their crops would get much needed rain; however, it would not be rain that fell from the sky, but grasshoppers. Laura describes, “Plunk! Something hit Laura’s head and fell to the ground. She looked down and saw the largest grasshopper she had ever seen. The huge brown grasshoppers were hitting all around her, hitting her head and her face and her arms” (On the Banks of Plum Creek, 194). These grasshoppers, called Rocky Mountain Locusts, rained down on the Minnesota prairie and decimated the land. They would eat everything green in their sight, like leaves, plants, and Pa’s crops. Wilder mentioned that because of these locusts, Pa had to make the 100 mile walk back east to find work. The family was affected by the same grasshoppers the next year. According to the article, Locust, by Jeffrey Lockwood, these locusts would become mysteriously extinct in the 1870’s after a wetter climate came into affect.
Jeffrey Lockwood, a science and humanities professor, wanted to solve the years long mystery of the Rocky Mountain Locusts, calling it “the quintessential ecological mystery of the North American Continent.” Lockwood goes on to explain that this breed of locust was at its greatest abundance on the Great Plains, even rivaling the bison population. He believed the dry weather caused the locusts to come baring down on farmers, sending them into a financial mess.
At the time, the U.S. government decided they needed to do something about the locusts. Although they had given relief to some of the farmers affected, it was not enough. They named three men to the Entomological Commission: Charles Valentine Riley, Cyrus Thomas, and Alpheus Packard. It would be their job to gather information about the locusts, research them, and find a solution to the problem. The three men did not disappoint. They found a large sum of information regarding the locusts’ “ecology, behavior, anatomy, reproduction, and distribution of the locust, and suggested practical ways for the farmers to battle the insects” (Hopkins). The men were about to publish their findings; however, in the late 1870’s the locusts went extinct. The drought had disappeared and the locusts disappeared with it.
Since their extinction, many theories have been put out to explain why it happened. According to BioScience, one of the biggest theories was that the locusts were somehow connected to the bison. When bison started to disappear in the American West, so did the Rocky Mountain Locust. The two species coexisted on the Great Plains for centuries. Maybe bison somehow altered the grasslands to favor the survival of the locust. Another theory involved alfalfa, which grasshoppers considered tasty. In studies, it showed that alfalfa was damaging to the growth of the locust in its premature stages. Therefore, it was the culprit on why the locust went extinct. Lockwood, the author of Locust, offered a new explanation. He believes that, “cattle grazing and homesteaders’ cultivation of restricted region of the plains-the permanent breeding grounds of the insect- during a population recession of the locust in the 1880’s may have irreversibly disrupted locust reproduction.”
While we may never know the true cause of the Rocky Mountain Locust’s mysterious extinction, we have a better idea of what may have happened. Like Laura’s family, these insects affected thousands of farmers and changed the course of history.
Hopkins, Theodore L. “Extinction of the Rocky Mountain Locusts.” BioScience, https://academic.oup.com/bioscience/article/55/1/80/248302. Accessed 30 May 2018.
Lockwood, Jeffrey. Locust, New York, Basic Books, 2004.