100 years ago, scientists captured the last live sample of a Rocky Mountain locust. Huge swarms of the insects devastated farms in Minnesota and much of the western half of the country throughout the 1800's. They ate everything in their path- from wheat fields and apple trees to fence posts and even laundry hanging out to dry. In 1875, a swarm 1,800 miles long and 110 miles wide moved across the country - the largest ever recorded. But the species vanished just a few decades later. Wyoming University entomologist Jeff Lockwood says the Rocky Mountain locust is the only pest species humans have driven to extinction: