Locust

by Jeffrey A. Lockwood

  Whereas flamboyance could be a delightful quality in a dinner guest, the staid Department of Agriculture had little tolerance of showboating. Riley’s success in making direct appeals to Congress during the formation of the Entomological Commission convinced him that direct lobbying was a viable tactic, a singularly appalling approach within the chain-of-command structure of the USDA. The department was headed by William G. LeDuc, a Civil War general who was constantly irritated by his insubordinate chief entomologist—and by the shenanigans of his staff. The department head enjoyed giving tours to important visitors and especially liked taking his guests to a box of pinned specimens of the Rocky Mountain locust, the creature of greatest intrigue and interest to high-ranking officials. LeDuc would make a beeline to this one box, whose location he knew, read the Latin name aloud for his visitors, open the box with a flourish, and show the contents with the portentous pride of a learned expert. Just prior to such a tour, one of Riley’s assistants—encouraged by his boss’s defiance of authority—altered the position of the boxes as a practical joke, leaving LeDuc confused and embarrassed.

  Throughout his seventeen years with the USDA, Riley was constantly in hot water because of his impatience with bureaucratic bungling and his intolerance of inefficiency. He resented administrative constraints on his program, which led to his resigning twice. The first time came after an elaborate scheme to secure his appointment as Assistant Secretary of Agriculture failed and Riley became so embittered that he was “allowed to resign.” After a change of administrations Riley was reappointed to his position as Chief Entomologist. However, he resigned in a “fit of temper” some years later over accusations that he had violated travel restrictions and deceived his superiors. Such conflicts surely exacerbated his bouts of “nervous exhaustion,” which frustrated him terribly. But despite these difficulties—or one might argue that, in part, because of the rabid intensity that led to them—Riley was able to create a legacy of economic entomology that continues to define this field.

  His rapidly growing program made tremendous advances in terms of new insecticides, machinery, and biological control methods. Perhaps his most famous accomplishment was saving the nascent California citrus industry from collapse under the ravages of the cottony-cushion scale. This fecund insect arrived in 1868, and within twenty years it had devastated citrus groves throughout the southern part of the state. The scale had been accidentally introduced from Australia, a key fact that Riley was able to deduce from his understanding of ecology, biogeography, and entomology. He convinced the California Fruit Growers Convention to appeal to Congress for assistance through the USDA. Riley suspected that the solution to the problem lay in the insect’s native land, and he also knew that the appropriation bill for his agency had a rider prohibiting foreign travel (aimed specifically at Riley and his junkets). Riley, of course, was undeterred. He used federal funds to have one of his field agents travel as a putative representative of the State Department to the International Exposition in Melbourne, his actual purpose being to find natural enemies of the scale. The man shipped back parasitic flies and predacious ladybird beetles. After successful field-cage experiments, thousands of the small beetles were distributed across southern California. Within months of releasing these voracious predators, Riley knew he had achieved what has been called “the greatest entomological success of all time.” This was the world’s first case of “classical” biological control (the suppression of an exotic pest by introducing a natural enemy from its homeland), and the method has become one of the most effective and widely used pest management strategies in modern agriculture.

  Riley’s innovations in terms of the nation’s agricultural and scientific infrastructures rivaled his purely scientific advances. To his other duties, he added the office of honorary curator of entomology to the Smithsonian Institution. This position allowed him to found the U.S. National Insect Collection. Today, the museum’s 25 million specimens are overseen by ten Smithsonian curators and another eighteen specialists from supporting agencies. Riley advocated the creation of a system of agricultural experiment stations, which were manifested in the Hatch Act establishing these facilities in the Land Grant Colleges of Agriculture across the United States. With the dawn of this immense network of educational and research centers, Riley played a powerfully influential role in defining these organizations via their staffs and mandates. A branch unit in economic ornithology arose because of Riley’s insistent demands, and this office became the Bureau of Biological Survey and then metamorphosed into today’s U.S. Fish and Wildlife Service.

  The USDA’s elevation to cabinet status in 1889 may not have been a direct consequence of Riley’s work, but his high-profile efforts were vital to the growing credibility of the agency. As for his own unit, Riley set a such trajectory for growth that the Division of Entomology’s budget increased 100-fold by the turn of the twentieth century. Whereas in 1876 Congress had anguished for weeks over the appropriation of $18,000 to create the first Entomological Commission, in 1929 it required only a few hours of deliberation to provide $750,000 to fund an eradication program for the Mediterranean fruit fly in Florida. Today, of course, the investment of human and material resources in economic entomology is on the scale of thousands of scientists and tens of millions of dollars.

  After Riley’s second resignation, he began to fade from public view, devoting his time to curatorial work at the Smithsonian—an ironic decision in light of his antipathy for Townsend Glover’s priorities. A year after stepping down, Riley and his fourteen-year-old son were speeding down an incline on Columbia Street in Washington when the front wheel of the father’s bicycle struck a stone and he was thrown over the handlebars. Riley’s head struck the pavement and he died within hours. At the age of fifty-one, America’s greatest entomologist was dead, killed in the prime of his life by a freak accident, just like his mentor, Benjamin Walsh.

  The obituaries and memories of Charles Valentine Riley were a carefully blended mixture of deep respect and personal distance. He had been a great scientist, but his passion and ambition did not allow for close friendships. A Canadian entomologist who turned down an invitation to take over Riley’s post in the U.S. Department of Agriculture offered perhaps the most tactful and honest appraisal of his obstreperous friend and brilliant colleague: “As an economic entomologist, take him all in all, he was far and away the most eminent that the world has ever seen.”

  As if in counterpoint to the Lord of the Locusts, the swarms of insects had continued to decline in notoriety during Riley’s rise to fame. The insects that had been the springboard of the great scientist and the entire field of entomology were now dormant. Some believed that the management methods tested and recommended by Riley and his fellow commissioners were to be credited for the continuing recession. However, like superstitious gamblers, many agriculturalists held to a “slot machine” view of nature. They were sure that as each passing year yielded few locusts, a “jackpot” outbreak became more likely. And the insects seemed periodically poised for an encore. A swarm descended on Otter Tail County, Minnesota, in 1888; locusts infested farming communities in middle and eastern Nebraska (including the state capital) in 1892; and spotty infestations were seen in Iowa. To many farmers, these small incursions were simply omens of a massive invasion just around the corner. Now, with Riley gone, would the locust return in a grand reprisal?

  8

  The Locust Disappears

  NORMAN CRIDDLE IS BEST KNOWN TO THE WORLD through his grasshopper antidote, which was widely promulgated throughout the western states and provinces in the early 1900s. What came to be known as the “Criddle mixture” was a rather simple—and absolutely disgusting—concoction.

  The recipe began with measuring out a pound of Paris green. Although evoking the romance of springtime in the heart of France, the name for this essential ingredient in Criddle’s recipe has a malevolent origin. Copper acetoarsenite was originally used as a bright green pigment in wallpaper, but in the mid-eigh
teenth century, the French discovered its potent insecticidal properties. Another arsenic-based pesticide was given a similarly enticing name: Calcium arsenite was called London purple. According to Criddle’s recipe, a pound of the Parisians’ poisonous powder was added to fifty pounds of horse manure, along with a pint of molasses, and mixed thoroughly (one didn’t want lumpy batter).

  This mess was then shoveled or otherwise pitched from a wagon as it passed through a field infested with grasshoppers. The manure provided a rather palatable—at least, to grasshoppers—carrier for the Paris green, and the molasses appealed to the insects’ sweet tooth. An “improved” Criddle mixture was developed in 1917, in which a half dozen lemons or oranges were substituted for the molasses, although it was never entirely clear whether fruit juice represented a better feeding stimulant than molasses.

  Entomologists rarely achieve much notoriety. Perhaps having a poisonous blend of horse manure named after you is better than anonymity, but this is surely one of the least celebrated paths to fame. Criddle knew that he had been oddly immortalized via his mixture, but he did not know that he would be associated with a rather more pivotal event in the history of the frontier—and particularly, in the story of the Rocky Mountain locust. But then, Criddle’s life was one of very peculiar circumstances and events.

  Norman Criddle was born in Addlestone, England, in 1875. His father, Percy, was educated in law, medicine, arts, and languages. His mother, Alice, was a graduate of Cambridge University, with a specialty in Sanskrit. Although Norman was Alice’s first child, he was Percy’s sixth (eventually, Percy would father thirteen). Evidently, Percy was highly attracted to both good books and intelligent women—the latter weakness extending beyond the propriety of Victorian England. Having courted Alice in London and gained her affections, Percy left to study in Heidelberg. There, he commenced a love affair with Elise Vane, who had received her education in Europe’s most prestigious universities. Upon completing his studies in Germany, he returned to England with Elise and their five children—and he reestablished his relationship with Alice. Shortly thereafter, he proposed to her, hiding the existence of his other family until after the wedding. In an understatement, the degree of which is only possible in a British account of family history, we learn that “the discovery came as quite a shock.” But Percy was apparently both a fertile and a resourceful man. He managed to keep his two households separate and their simultaneous existence secret in the social circles of London, where he worked as a wine merchant. For his part, Norman spent long hours in the garden, learning the names of dozens of plants and insects by the time he was three years old.

  After many years of reasonable success in the world of business, Percy decided to start a new life with his two families in Canada. Norman, whose health was fragile at the best of times, suffered immensely on the voyage, but he managed to survive. The overland trip from New York, north to Winnipeg, and then out to Manitoba also was arduous, but the family arrived safely in Manitoba. The only things they lacked upon their arrival in the Wawanesa area were any skills relevant to pioneer life. They were cultured Victorians, intensely interested in intellectual pursuits, sports, and leisure—hardly the foundation for a prairie farm family.

  The family’s funds were dwindling, but they had more money than know-how. So they paid the neighbors to construct a log house for the two families. What they lacked in ability, the Criddles and Vanes made up for in gumption and labor, and the farm slowly took shape. In time, Percy replaced the log home with a mansion, and Elise and her children moved to a separate house at the edge of the Criddle homestead. The de facto polygamy was wearing on the emotional state of the adults, although the children got along together quite well. In a truly impressive conspiracy of parental misdirection, the children were blissfully unaware that they were half brothers and sisters—a fact that might never have been revealed to them had there not emerged a budding romance between one of the Criddles and one of the Vanes. Upon learning of their relationship, one can imagine that they were every bit as shocked as Alice had been many years earlier.

  With his farming enterprise flourishing after much trial and error, Percy put in tennis courts and a nine-hole golf course on his estate. Along with his family, the surrounding community enjoyed these facilities. The open-air life on the prairie invigorated Norman. The frail boy was growing into a strapping young man.

  Percy continued to encourage Norman’s interest in the natural sciences. The elder Criddle made systematic observations of the plants and animals in his region, but perhaps his greatest infatuation was with the heavens. He had a telescope shipped to him from England and spent long hours peering into the night sky. Percy dreamed of becoming a famous scientist, and when the world-renowned naturalist and writer Ernest Thompson Seton visited the Criddles, Percy hoped that his guest would facilitate the publication of his observations of the local flora and fauna. His ultimate goal was to thereby gain entry into the prestigious scientific societies in the eastern cities. However, Percy’s dream never materialized, and it was his son Norman who would be recognized for his contributions to the world of science.

  Rather than skating or playing cricket with his siblings, Norman devoted much of his youth to developing and refining his science and art. He learned both the skills of making incisive observations of the natural world and the methods of creating beautiful renderings of the prairie. Soon, he was held in high regard by zoologists, and his paintings of plants brought him considerable fame. In the course of his naturalistic studies and art, Norman made extensive collections of the plants and insects of Manitoba. And it was one such venture in the summer of 1902 that immortalized him in the history of science.

  On July 19th of the fateful year, Criddle collected a male and female Melanoplus spretus from his father’s estate and labeled the specimens according to the standards of museum preservation. Through an untraceable path, over the course of half a century, these specimens found their way into the insect collection of the Smithsonian Institution. Meanwhile, Norman turned his attention to conservation, and he became one of North America’s earliest environmentalists trying to preserve Canadian forests and habitats. So it is ironic that his name is most commonly associated with a poisonous manure-based concoction for killing insects. But because of those two specimens housed in America’s greatest museum, we also know that this kindly lover of nature can be more fittingly described as the last man to have seen a living Rocky Mountain locust.

  WHY NOBODY NOTICED

  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 locust
s 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.