It defies imagination. A biblical-scale plague of locusts an estimated 500,000 square kilometres in size swept across the U.S. Midwest and into parts of Western Canada in 1875. The ravenous insects ate virtually everything in their path from crops to cloth. Described as a living eclipse of the sun, it is believed to have been the largest insect swarm in recorded history. Perhaps even more extraordinary, within 25 to 30 years of this legendary natural event, the Rocky Mountain locust (Melanoplus spretus) was declared extinct.