Rocky Mountain locusts, often arrived in great swirling masses that resembled storm clouds and went on to destroy countless acres of crops to the tune of over $200 million in damage.
Here's the odd part, though. By 1902, the locusts were gone. Gone, as in extinct.
So I began to read several articles as to how such a widespread population of bugs could just suddenly disappear. No one seems to know for sure, but according to a New York Times article and this article, theories range from plowing/irrigation practices to farmers bringing in "insect eating birds". How could a swarm once described as being "1,800 miles long and 110 miles wide" disappear due to increased plowing?
I have driven along long stretches of Interstate 90 over the years. I can tell you there is an awful lot of open space between the South Dakota/Minnesota border and Washington state, and it isn't all farmland or mountains. Somehow I think there is a lot more to this story than just birds and plowed land.