Lessons from the locusts

By Gary Raham
Nature Writer and Illustrator

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Most people know about the near extinction of the American bison that reduced perhaps 30 million animals to a few hundred individuals in the 1880s. Fewer people know, or care, about the extinction of an agricultural pest species, the locust, from North America just a couple of decades later.

Humans caused both events as they manifested their destiny across the American West. Some might even consider the latter extinction a human victory (even if unintentional) over a devastating pest, but the University of Wyoming professor who unraveled the details of the demise of locusts, Jeffrey A. Lockwood, said his research provides a few lessons our species should take to heart.

It's hard to love a locust--another name for a migratory grasshopper with a whopping appetite. Virtually every continent entertains a locust species with a story to tell--like the Biblical account of locusts that plagued the pharaohs.

In the United States in the 1870s clouds of locusts periodically darkened the skies. They rained from the heavens like hail, sticking to clothes, thrashing about in people's hair, greasing the rails of trains with their dying bodies, not to mention denuding landscapes of plants for miles in every direction, including cropland. In 1876, the U.S. Congress declared locusts "the single greatest impediment to the settlement of the country."

Settlement of the West fueled economic growth in the latter half of the 19th century. Financier Jay Cooke, owner of the Northern Pacific Railroad, induced farmers to move west, failing to mention that most western lands were short on water and subject to periodic waves of locusts. In a financial meltdown called the panic of 1873, not unlike the one we are experiencing today, the nation endured a severe depression.

The locust outbreaks that occurred between 1874 and 1877 didn't help. They caused $200 million in damage ($116 billion in today's money). People tried everything to control the locusts: They assembled grasshopper armies of able-bodied men who collected bounties for locust corpses; they tried burning locusts, crushing them, plowing up and even dynamiting the eggs female hoppers laid in the soil of devastated farmland...and they prayed. Locust plagues continued, however, through the 1880s. For no apparent reason, they began declining in the 1890s. The last reported swarm in North America occurred in Manitoba in 1902.

People are quick to forget a problem that no longer exists. Besides, World War I, the Dust Bowl years and the Great Depression served as great distractions.

Professional entomologists have discovered that the migratory and breeding phases of locusts look quite different. Most thought the breeding phase of the locust still existed somewhere, and the conditions for expansion, for whatever reason, no longer existed. But an entomologist at the Smithsonian Museum found that unique genitalia in locust males could be used to distinguish Melanoplus spretus from sister species, thus allowing researchers to rule out closely related candidates. The locust species that had once poured across the prairies in clouds containing billions of individuals had apparently become extinct in as little as a decade.

Sometime in the 1980s, professor Lockwood decided unraveling this mystery would be both professionally challenging and interesting. By the time he was done, the project had become a personal quest that ranged from the dusty archives of various museums to glaciers in the Wind River Range of Wyoming that disgorged their collection of ancient locusts in the melt water of a new and warming century. Lockwood told his tale well in a book called "Locust, The Devastating Rise and Mysterious Disappearance of the Insect That Shaped the American Frontier" (Basic Books, 2004).

Here is the cut to the bottom line: His research led him to believe, and subsequent studies have supported the idea, that locusts became collateral victims as farmers and miners settled in and plowed the soil of the lush river valleys of the Rocky Mountains during the gold rush years. These areas supported locusts in the nonmigratory phase of their life cycle. We couldn't kill these insects on purpose, but unintentionally did so during our own expansion. Locusts were most vulnerable in their mountain breeding ground refuges. When those disappeared, so did their swarming abundance.

Lockwood points out that large numbers can't save a species if they are cut down when they are weakest--when their sanctuaries somehow transform from safe havens to killing fields. As humans, we often pride ourselves for our intelligence and adaptability. Locusts were quite adaptable themselves. They ate 50 different kinds of plants in 12 different families--not to mention leather, fabric, paper and wool when they got extra hungry. Human populations worldwide depend on three grains: corn, wheat, and rice--and they are all in the grass family. They grow in huge monocultures, often in lowlands subject to flooding or near expanding deserts. In a very real sense, the entire Earth constitutes a lush sanctuary for our species in a mostly hostile universe. Perhaps our vaunted intelligence can save us from destroying our last refuge--if we recognize quickly enough that to do so we must ensure that the complex, intertwined living systems that maintain our special planet, including our energy-hungry civilization, remain intact and function properly.

Perversely, it might seem, Lockwood harbors a bit of sympathy for the locusts that plagued our 19th century ancestors. He captured and identified a few individuals in Yellowstone National Park that he described as the locust sister species Melanoplus bruneri--yet they had some features that made him think twice about his identification.

Nevertheless, he released them.

Perhaps it's not impossible to love a locust after all.