We’re all familiar with them…those pesky grasshoppers that never seem to know which direction they’re going to jump. Ugh! Definitely not one of my favorite insects. I started musing about the differences between grasshoppers and locusts and found some interesting information that I wanted to share with you. They’re actually both grasshoppers- species of the Acrididae family. But locusts have a swarming phase that can happen under suitable conditions of drought followed by rapid vegetation growth. These circumstances trigger serotonin in their brains which sets off dramatic changes in color, breeding and feeding, and their solitary behavior changes to what entomologists call gregarious . Overcrowding then occurs and the transformation of the locust to the swarming form is brought about by several contacts between insects per minute over a four-hour period.
We all know what happens then…
For U.S. agriculture, the past holds some episodes of this activity. The Rocky Mountain locust periodically hit farmers from California to Texas to Minnesota. In 1875 the largest swarm in history was recorded over the Midwest – 198,000 square miles (California covers nearly 164,000 square miles). It was estimated to contain several trillion locusts and most likely weighed several million tons. Farmers tried in vain to fight the swarms with fires and metal scoops covered with tar or molasses. Wild West Magazine wrote:
The locusts soon scoured the fields of crops, the trees of leaves, every blade of grass, the wool off sheep, the harnesses off horses, the paint off wagons and the handles off pitchforks…The locusts, farmers grimly quipped, “ate everything but the mortgage.”
But only 27 years after this record swarm the Rocky Mountain locust was extinct with the last sighting recorded in 1902. The reason? Scientists debate about it, but the general conclusion points towards farmers. They put more and more acreage under the plow which prevented the land from being a host to locust eggs.
But not even extinction can guarantee that these events will never happen again. On July 31, 1931, a swarm of grasshoppers destroyed millions of acres in Iowa, Nebraska and South Dakota – already in the midst of a bad drought.
Since this time, swarms have not been seen in the United States. If I had to pick a grasshopper over a locust, I guess I’d stick with the solitary species…
-Terry Olson, Titan Machinery
Resources:
https://en.wikipedia.org/wiki/Locust
http://www.westernfarmpress.com/blog/locust-swarms-bring-back-past-us-farmers
http://www.history.com/this-day-in-history/grasshoppers-bring-ruin-to-midwest