On the last week of July in 1931, swarms of grasshoppers decimated croplands throughout Nebraska, Iowa, and South Dakota. The Great Plains, already suffering from an extreme drought, saw millions of acres fall victim to this small yet mighty pest. According to historical archives, the July 1931 swarm was said to be so thick that it “blocked out the sun and one could shovel the grasshoppers with a scoop”. Fields of crops, especially corn, were razed to the ground by these insects. Rosebud and south central South Dakota were the most affected areas of the state according to the Huron Daily Plainsman.
East River was left relatively unscathed by the swarms. Many newspapers of the day, including the Aberdeen News and the Redfield Journal-Observer, proposed that the pheasant population maintained a check on the grasshopper populations in the eastern region of the state. One notable op-ed stated "For this, the residents of large areas in South Dakota owe a debt of gratitude to the much maligned pheasant. This year, he is demonstrating his excuse for being. "
Grasshopper and locusts swarms have not been seen in the United States since the 1930s.
For more insights on how a swarm of grasshoppers or locusts behave, see this description by Professor Jeff Lockwood of the University of Wyoming.
Interested in other insect pests in South Dakota? Check out our resource page on the Mountain Pine Beetle.