Locust (22 page)

After the staggering outbreaks of the 1870s, the Rocky Mountain locust irrupted sporadically until the turn of the century. The realization that the locust was gone dawned very slowly in America’s heartland. It seems incredible that the loss of an insect that eclipsed the sun would not be readily apparent and even widely hailed. By
way of modern comparison, if in the course of a few years hurricanes stopped pummeling the coastline of the United States, we’d surely catch on to the absence of these natural disasters. There would be congressional investigations, research initiatives, media speculations, and plenty of armchair science going on. So, how could the disappearance of a creature as obvious as the Rocky Mountain locust go unnoticed?

 

Although one might guess otherwise based on patterns of coastal home building, hurricanes strike the eastern seaboard every year. Sometimes there are significantly more or fewer storms than “normal” (which works out to about six hurricanes between June and November), and sometimes they arrive with unforgettable fury. The names Andrew, Camille, and Hugo stir memories of awesome power and incomprehensible destruction. As sure as the waters of the Atlantic warm in late summer, the tropical storms will develop, and some will grow into full-fledged hurricanes. Locust outbreaks were quite another story. Many years could pass without swarms of these creatures sweeping down from the Rockies. At least some western states reported no locusts for periods of five to ten years. Although there were small swarms most every year, full-fledged plagues were erratic events. So, when the storm clouds of locusts failed to darken the skies over the Great Plains for years, people were not particularly encouraged—or surprised.

We would be less likely to notice a lack of hurricanes if, during the time of their absence, tornadoes, blizzards, droughts, and floods occurred with increasing intensity. An increase in one type of disastrous weather event might well obscure the disappearance of another. While the Rocky Mountain locust was fading into the past, other grasshoppers rushed to fill the empty niche—ready and able to take the locust’s place in harassing prairie farmers. Ecologists use the term
competitive exclusion
to describe the phenomenon in which species prevent one another from exploiting the same set of resources. The legendary American ecologist Aldo Leopold wrote in his
Sand County Almanac,
“Just as there is honor among thieves, so there is solidarity and co-operation among plant and animal pests. Where one pest is stopped by natural barriers,
another arrives to breach the same wall by a new approach. In the end every region and every resource get their quota of uninvited guests.”
⁴

This exploitation of opportunity is a bit like the world of business. For a while there might be both eight-track players and cassettes, or Betamax and VHS formats, but eventually competitive exclusion takes hold. In short order, the niche is filled and fiercely protected by one or the other of the product manufacturers. And if the Rocky Mountain locust of the computer world suddenly disappeared—if Microsoft collapsed—we could be sure that another operating system would quickly fill the gap. Likewise, when the American chestnut—the dominant hardwood tree of the eastern United States—disappeared from the landscape in the early half of the last century because of a blight, our forests filled in with other species. It seems that nature abhors a vacuum in ecology, as well as in physics.

Serious outbreaks of two close relatives of the locust stifled whatever sigh of relief might have come with the demise of the Rocky Mountain locust. The migratory grasshopper,
Melanoplus sanguinipes
, and the redlegged grasshopper,
Melanoplus femurrubrum,
were waiting in the wings. With the curtain falling on the locust, these other grasshopper species rushed onto the stage. Minnesota’s Agricultural Experiment Station reported terrific infestations of the migratory grasshopper in the early 1890s, and farmers in western Colorado, Kansas, and Nebraska battled grasshoppers at the turn of the century. In what seemed a weird act of insectan revenge, for the three years after Norman Criddle caught the last known Rocky Mountain locusts, farmers in Manitoba were inundated with grasshoppers.

Farmers in the Plains states barely had time to relish their scattered victories before the grasshoppers resurged in 1908 and persisted until 1912. And as grasshoppers were retreating in the United States, they were advancing again in western Canada, with a major outbreak lasting from 1912 to 1914. The two species that ravaged the farms of the Midwest were joined by others in Canada, including the two-striped grasshopper and the clearwinged grasshopper. Five years later,
Kansans plowed thousands of miles of roadsides and fencerows to destroy grasshopper eggs. And when this campaign failed to control the outbreak, they applied nearly 7 million pounds of poison bait, including the “Criddle mixture,” to an area larger than the state of Delaware. Sporadic grasshopper damage was reported across the West throughout the 1920s.

Grasshoppers and drought devastated the Great Plains during the “Dirty Thirties,” and what the grasshoppers didn’t eat, the dust covered. In Missouri, the grasshopper damage from 1935 to 1938 was termed the “worst since 1874-76,” an allusion to the days of the Rocky Mountain locust. From 1938 to 1940 vast areas of the West were crawling with infestations of the migratory grasshopper. Some of these populations matured into locustlike swarms capable of traveling thirty miles or more a day. In the midst of this outbreak, New Mexico and Texas mobilized their National Guards to deliver poison bait to afflicted farmers and ranchers, echoing the role of the military as a means of provisioning agricultural communities sixty-five years earlier. Kansas alone lost $21 million worth of crops to the grasshoppers in a single year.

As damaging as these grasshopper infestations were, they paled in comparison to the psychological, sociological, political, and economic damage wrought by the Rocky Mountain locust. The grasshoppers were largely of local origin, and the swarms of migratory grasshoppers were only a pallid imitation of the cataclysmic inundations by the mighty locust. Because the intensity and scale of destruction by grasshoppers were more limited and the tools for pest management were better known (in large part as a result of the work of the U.S. Entomological Commission, as at least some of their methods were applicable to these insects), grasshopper infestations were less traumatic. Furthermore, agriculture was on a more stable footing, and established farms had a greater economic capacity to battle the grasshoppers and absorb losses than the homesteaders had just a few decades earlier. Finally, state and federal governments had developed rather sophisticated capacities for assessing and mobilizing resources during natural disasters. Although grasshoppers could not equal the locusts when it came to provoking fear and causing damage, there was enough similarity to exploit allusions to the old enemy in securing resources to battle the new foe.

The political motivation for the federal government to subsidize the control programs by providing poison bait harked back to the days of the Rocky Mountain locust. Some of the allusions were reminiscent in their language, crossing into biological hyperbole, such as the impassioned editorial in the
Minneapolis Tribune
:

Even the Secretary of Agriculture got into the act. Arthur Mastick Hyde was born in the midst of the Rocky Mountain locust’s grand finale and had served as the governor of Missouri. So perhaps Hyde can be forgiven for his letter to Congress in 1932 in which he allows his language to slip, referring to the notion that any control campaign should
“poison the young locusts as they first emerge from the egg beds and before they have any opportunity to migrate from such areas in the fields.” Most of the rest of his letter refers to the insects as “grasshoppers” and suggests that it might be too late to act, but his use of the term
locusts
early in his message was surely a provocative linguistic tactic.

Within Congress, references to the locust plagues of fifty years earlier were even less subtle. Perhaps the most dramatic testimony was offered by Edward Thomas Taylor from Colorado. Serving in the House of Representatives for thirty-two years (no one from his own Democratic Party dared oppose him), Taylor carried great political weight in Congress. He authored the Taylor Grazing Act, which is the law that still governs livestock grazing on public lands. His personal tale, along with his enormous political will, undoubtedly influenced his fellow members of Congress in their decision to provide assistance in battling the grasshopper outbreak: “Mr. Speaker, like the gentleman from Texas, I had a sad personal experience with grasshoppers. When I was a small boy [Taylor was born in 1858] my parents located on the extreme frontier of northwestern Kansas, and for three years everything we planted was eaten by grasshoppers [almost certainly the Rocky Mountain locust]. We were compelled to practically walk out of that country, disheartened and completely bankrupt, so I know what this scourge is.”

To obscure matters even more, the migratory and redlegged grasshopper looks a lot like the Rocky Mountain locust. Although they don’t form the breathtaking swarms or reach the astounding densities, there can be a hundred or more per square yard, stretching across thousands of acres. In the early decades of the twentieth century, many agriculturalists assumed that the grasshopper infestations that devastated their crops were localized outbreaks of the locust. Even species utterly unlike the Rocky Mountain locust—at least to the eye of an entomologist—were confused with this species. In Minnesota, farmers were convinced that they were being overrun by the locust when the culprit was the Carolina grasshopper—a species that is dusty brown (rather than olive green), has jet-black hindwings (rather than colorless wings), and is twice the size of the Rocky Mountain locust. Utah farmers confused infestations of the clearwinged grasshopper, which does bear a very superficial resemblance to the Rocky Mountain locust, with their old nemesis.

Grasshopper problems—and federal subsidies for their control, rooted in the cultural memory of the locust plagues—have continued sporadically into the present. When I joined the entomology faculty at the University of Wyoming in 1986, grasshoppers were once again devastating western agriculture—and 20 million acres of insecticide treatments did little to stem the tide. A grasshopper outbreak in 1998 encompassed 430 million acres of the West (an expanse ten times larger than New England or about the combined areas of France, Germany, Italy, and Spain) and caused $500 million in damage. And the outbreak unfolding across the West at the turn of the twenty-first century once again released a flood of federal funds. So perhaps it is no wonder that people failed to note the passing of a locust, when its relatives were trying so valiantly, albeit less dramatically, to fill those big, empty shoes.

 

The social psychology of the news has changed little in the past century. Let’s say that this summer no hurricanes strike our shores. We wouldn’t expect a headline announcing, “Good News: No Killer Storms Yet.” Even if we went into early fall without a hurricane, it seems unlikely that their absence would galvanize the media. If there are no hurricanes with which to draw viewers and thereby sell advertising on the nightly news, surely there is an epidemic, a war, or a political scandal. Thus, it is hardly surprising that when locusts didn’t return to the farmlands of the Great Plains, the newspapers failed to proclaim the good news. The absence of locust swarms was noted in passing within a few agricultural reports. But even technical publications are reluctant to report what scientists refer to as
negative results
. Scientific journals don’t tend to publish papers that list a whole bunch of chemicals that won’t cause cancer, species that aren’t becoming extinct, or pests that aren’t outbreaking.

Even when the grasshoppers were newsworthy in their depredations, they had the cards stacked against them in terms of publicity. When the insects were booming, as in the early 1900s, rebellions, earthquakes, monopolies, and World War I became the crises du jour. In fact, grasshopper and locust outbreaks often correspond with other natural and economic disasters. These insects flourish during droughts. And crop failures may have precipitated, or at least exacerbated,
economic depressions, especially during more agricultural times. Thus, reports of these insects were often moved aside for more compelling accounts of human suffering.

If hurricanes were to decline in frequency and severity, our National Weather Service would surely note the change. After all, we have a National Hurricane Center that employs a cadre of scientists to keep track of these storms, and they’d start getting nervous if we ran out of hurricanes. But with the collapse of the Rocky Mountain locust outbreak in the late 1870s, the coordinated national survey of the U.S. Entomological Commission dissolved as USDA entomologists turned their attention to other pests and the state entomologists returned to local problems. In short, it wasn’t anyone’s job to notice that the locusts weren’t still around. But this isn’t to say that various folks didn’t eventually catch on.