Rocky Mountain Locust - Extinction

Extinction

The last major swarms of Rocky Mountain locust were between 1873 and 1877, when the locust caused $200 million in crop damage in Colorado, Kansas, Minnesota, Missouri, Nebraska, and other states. The cause of their extinction was probably the plowing and irrigation by settlers that disrupted the natural life cycle of the insects in the very small areas where they lived in between swarms. Reports from this era suggest that farmers killed over 150 egg cases per square inch while plowing, harrowing or flooding.

Because locusts are a form of grasshopper that appear when grasshopper populations reach high densities, it was theorized that M. spretus might not be extinct, that "solitary phase" individuals of a migratory grasshopper might be able to turn into the Rocky Mountain locust given the right conditions. However, breeding experiments using many grasshopper species in high-density environments have attempted to invoke the famous insect without success. Analysis of mitochondrial DNA from museum specimens and related species suggests that the Rocky Mountain locust was a distinct and now extinct species, possibly closely related to the Bruner spurthroat grasshopper (Melanoplus bruneri).