In the years immediately preceding Albert’s Swarm, a terrific drought had settled over the central United States. In 1873, just seven and a half inches of rain fell on Wallace, Kansas—the driest year on record. Dodge City experienced its third driest year in history in 1875. Missouri farmers reported that in 1874 “it stopped raining in April and didn’t rain again till late October.” The twelve months from May 1874 to April 1875 comprised the eighth driest period in 150 years of Ohio weather records. The heat and dryness were devastating for farmers and ideal for locusts.
Although drought conditions fostered population growth in the locusts, a second climatic factor was necessary to create a locust swarm of such incredible magnitude. There had to be a constant, southerly wind to unite the insects over an immense area and maintain the coherence of the swarm for days on end during its northward migration. The monsoon weather that arises from the Gulf of Mexico might be suspected in this regard, but this meteorological event generally lacks essential elements of a June weather pattern. Not only does the monsoon typically develop later in the summer, but it also fails to sustain winds across a geographic scale necessary to propel a locust swarm from Texas to Minnesota. However, in the 1950s meteorologists discovered another annual event with the potential to have carried history’s greatest swarm: the Great Plains low-level jet.
This wind stream forms in late spring or early summer and extends into autumn. The 200-mile-wide flow of air is centered on Oklahoma and Kansas but stretches from the Gulf Coast to the Canadian border. This conveyor belt of air averages perhaps 10 miles per hour in the day and rises to 30 during the night—parameters that are consistent with those reported by Albert Child. The winds peak at about a thousand feet above the ground, again fitting with the scale of Child’s swarm. If no frontal systems move through the region, the Great Plains low-level jet blows for days on end. Furthermore, this wind system is strengthened by heat, as during a drought. Migrating birds are known to exploit this airstream in their northward journeys, and it seems nearly certain that the locusts did so as well.
So we can infer that the drought of 1874-1875 both fostered the buildup of locust populations and strengthened the jet that scientists call “one of the most prominent meteorological phenomena of the central United States.” Crowded into jittery populations spread across tens of thousands of square miles, the locusts almost certainly arose in separate swarms that were then coalesced by a wind stream that swept them into the perfect swarm.
By the 1870s, the nation was coming to realize that the Rocky Mountain locust was a tempestuous hurricane of insect life—that when these storm clouds shimmered on the horizon, a hail of hungry insects was coming. Although Albert’s Swarm was the greatest cyclone of locusts to sweep across the continent, Americans and Canadians had been painfully aware of this creature’s devastating capacity for some time.
Figure 2.1 An Introduction to Entomology by William Kirby and William Spence, 1859
WHAT’S IN A NAME?
The first popular book of entomology to be published in English was an imposing series of five volumes beginning in 1815. By the time of the seventh edition in 1859, this comprehensive text had been mercifully reduced to a single volume that retained the luxuriant language and engaging prose of the earlier formulations. And the title was no less opulent (Figure 2.1).
In this definitive coverage of insect biology, William Kirby (sometimes called the Father of Entomology) and William Spence (a renowned beetle collector in his own right, but second fiddle to Kirby) had not yet learned of the locust outbreaks in the New World. However, they devoted a considerable portion of their book to these insects’ depredations in the Old World. They took pains to convince the reader that although a single locust was hardly intimidating, in the collective these creatures had rightfully earned their rapacious reputation:To look at a locust in a cabinet of insects, you would not, at first sight, deem it capable of being the source of so much evil to mankind as stands on record against it. “This is but a small creature,” you would say, “and the mischief which it causes cannot be far beyond the proportion of its bulk. The locusts so celebrated in history must surely be of the Indian kind mentioned by Pliny, which were three feet in length, with legs so strong that the women used them as saws. I see, indeed, some resemblance to the horse’s head, but where are the eyes of the elephant, the neck of the bull, the horns of the stag, the chest of the lion, the belly of the scorpion, the wings of the eagle, the thighs of the camel, the legs of the ostrich, and the tail of the serpent, all of which the Arabians mention as attributes of this widely-dreaded insect destroyer; but of which in the insect before me I discern little or no likeness?” Yet, although this animal be not very tremendous for its size, not very terrific in its appearance, it is the very same whose ravages have been the theme of naturalists and historians in all ages, and upon a close examination you will find it to be particularly fitted and furnished for the execution of its office.
These early British scientists were not duped by the extraordinary accounts of the ancient Romans, but they were convinced that the emanations of dead locusts could induce epidemics. They faithfully reported Saint Augustine’s assertion that rotting locusts had caused plagues that killed 800,000 people in the kingdom of Masanissa 2,000 years earlier and nearly a million in Italy in 591 C.E. Although heaps of decaying locusts are not a source of human disease, Kirby and Spence’s accounts of famine are rather more convincing. They recounted the swarms that led to the deaths of 30,000 Venetians in 1478. To drive home the seriousness of locust plagues in their own time, they described how Yusuf Karamanli, the bashaw of Tripoli, raised a force of 4,000 soldiers to fight locusts (at about the same time that he was battling the U.S. Navy, which President Jefferson had sent in retaliation against the piracy that was humiliating his new nation and undermining its commerce). If the reader doubted Kirby and Spence’s implication that the gravity of a locust outbreak could justify mobilizing an army, so did some of the bashaw’s soldiers. But the authors explained that Karamanli was deadly serious about the situation “and very summarily ordered all to be hanged who, thinking it beneath them to waste their valour upon such pigmy foes, refused to join the party.”
Locust outbreaks have occurred on every inhabited continent. Europeans periodically suffered the invasions of several locust species into the last century, some of which were homegrown and others of which immigrated from Africa and Asia. However, modern pest management methods and conversion of natural habitats have largely ameliorated locust outbreaks in Europe. Africa, Asia, and Australia are still commonly plagued by various species of these insects, with outbreaks in Central Asia encompassing more than 6,000 square miles in 1999. Although the Australians have the most sophisticated locust management program in the world, the vast, uninhabited landscape makes finding and suppressing these outbreaks an immense challenge. South America is less frequently beset by locusts, but the grasslands of Argentina, Brazil, and Peru are prone to occasional infestations. Whereas parts of Mexico are sometimes overrun with a tropical locust related to those on other continents, the rest of North America hosted just a single, unique species of these insects, the Rocky Mountain locust.
The term locust is derived from the Latin, locus ustus, meaning “burnt place”—an allusion to the denuded landscape left in the wake of a ravenous swarm. If we think of life being sustained by oxidative metabolism, the slow burn of biochemistry, then perhaps associating locusts with conflagrations is remarkably appropriate. In a very real sense, a swarm of locusts is a metabolic wildfire burning tons of vegetation every day to fuel its migration. The family to which all locusts belong, the Acrididae, may also derive its name from this sense of acrid corrosion that was associated with the damage caused by these insects.
Locusts were then—and still are—mysterious creatures, whose sudden irruptions are their defining attribute. In biological terms, a locust is a type of highly mobile grasshopper with the capacity to attain enormous population densities and a proclivit
y for aggregating and traveling in bands (as immature nymphs) and swarms (as winged adults). Aside from belonging to the family Acrididae, which has 10,000 species worldwide, the 10 species of locusts are not taxonomically related. The locust’s survival strategy has evolved within several subfamilies around the world, although only North America was blessed with just a single species of locust—along with several hundred species of grasshoppers.
Not only are locusts haphazardly scattered throughout the evolutionary lineages within the Acrididae, they are also frustratingly difficult to define in discrete, ecological terms. In a sense, locusts are to grasshoppers as athletes are to humans. Nobody would doubt that a professional basketball player is an athlete, but what about a professional golfer or bowler? What about the dedicated amateur training for the Olympic curling team? And what about the weekend warrior on the softball field? Rather like being an athlete, being a locust is a matter of degree. Some creatures exhibit weak tendencies toward aggregating as nymphs or adults and others manifest the full-blown locust syndrome—the Rocky Mountain locust and the Desert locust of the Old Testament being classic cases at the extreme end of the locust spectrum. At the other end are the various garden-variety grasshoppers that placidly masticate our lettuce patches and bask in abandoned lots (the short antennae of these creatures distinguish them from related families of insects commonly found in pastures and fields—the katydids and crickets).
Locusts may not be readily classified, but entomologists are strident in their contention that this term should not be—as it often is—applied to cicadas. Cicadas are the stumpy, clear-winged insects that resemble gargantuan aphids and belong to the same order as their tiny cousins. Thus cicadas are in an entirely different insect order from the grasshoppers or locusts (Homoptera versus Orthoptera). This might seem a hairsplitting exercise, but consider that in mammals, elephants and shrews are also in different orders. The misnaming of cicadas as locusts originated in the late 1600s and has continued to the present day in some areas of the United States. The confusion is understandable from an ecological, if not a taxonomic, perspective. After all, the periodical cicadas emerge from the ground in staggering numbers and fill the forests with their incessant buzzing. If being a locust were simply a matter of being an insect herbivore that could suddenly attain incredible populations, then perhaps cicadas would qualify. But as opposed to true locusts, cicadas lay their eggs on plants (rather than in the soil), live underground as root-feeding nymphs for up to seventeen years (rather than living above ground and eating leaves and stems while maturing in a few weeks), feed sparingly as adults by piercing a plant with their elongated stylets (rather than feeding voraciously by biting and chewing their food), and remain in the vicinity where they emerged (rather than migrating in swarms).
The officially sanctioned, scientific name of the Rocky Mountain locust is Melanoplus spretus. This approved name was chosen by Benjamin Walsh in 1866, although entomologists had been variously referring to this creature for some time. The locust had been unofficially named a few years earlier by Philip Uhler, a Harvard-educated entomologist who was deemed America’s greatest hemipterist (Hemiptera being the order of insects comprising the true bugs—a group that might not leap to one’s mind as being associated with scientific greatness, but entomologists are a proud, if quirky, lot). He called the insect Acridium spretus (the genus Acridium was later changed to Caloptenus and finally to Melanoplus, which is the currently accepted name). In the twisted course of taxonomic history, this name was subsequently and rather surprisingly misprinted by another entomologist as A. spretis and later as A. spretum. Biologists take the scientific names of organisms very seriously, so the lackadaisical approach to the spelling of this species is unusual. Although Walsh used Uhler’s original spelling, the credit for naming the species goes to Walsh. As opposed to his predecessor, Walsh’s publication included a full description of the creature along with the name: A detailed characterization of an organism’s appearance is considered one of the essential components in creating a valid scientific name for a new species.
All scientific names must take a Latinized form, which facilitates international communication, keeps an otherwise dead language alive, and makes for interesting translations. In the case of the Rocky Mountain locust, the genus Melanoplus came from the Greek meaning “black armored.” Although the adult locust was more of an olive green, other species in the genus are decidedly darker, and all of these creatures are encased in a sturdy exoskeleton, so the name is quite appropriate. As for spretus, it derives from sperno: “to scorn, despise, or spurn.” And so, the Rocky Mountain locust was the despicable black knight of the continent—an abhorrent creature clad in dark armor that besieged the pioneers: a sort of eighteenth-century insect Darth Vader.
There was some debate as to the most appropriate common name for M. spretus. Early American entomologists, having a bone to pick with various grasshoppers in the United States, had already coopted the names “Detestable locust” and “Devastating locust” for other species (which were actually grasshoppers, but adding locust made them sound more formidable). Otto Lugger, the first entomologist of the Minnesota Agricultural Experiment Station, advocated the “Hateful grasshopper” (or locust) for M. spretus. However, the less evocative but more biogeographically informative name of “Rocky Mountain locust” came into widespread use and general acceptance. This name associated the creature with the apparent origin of its outbreaks—the imposing range of peaks that protruded from the fertile prairies like the exposed skeletal backbone of the continent. What better place than these brooding, mysterious mountains from which to launch the hated armored legions that descended upon the vulnerable frontier farms and homesteads?
For millennia, humans had perceived locusts as invading armies from far-off lands. The arrival of swarms appeared otherworldly, and their scope of destruction seemed godlike. Such a sense of unearthly foreboding and divine malevolence resonates throughout the Exodus account of the sixth plague of Egypt:Then the Lord said to Moses, “Stretch out your hand over the land of Egypt for the locusts, that they may come upon the land of Egypt, and eat every plant in the land, all that the hail has left.” So Moses stretched forth his rod over the land of Egypt, and the Lord brought an east wind upon the land all that day and that night; and when it was morning the east wind had brought the locusts. And the locusts came up over all the land of Egypt, such a dense swarm of locusts as had never been before, nor ever shall be again. For they covered the face of the whole land, so that the land was darkened, and they ate all the plants in the land and all the fruit of the trees which the hail had left; not a green thing remained, neither tree nor plant of the field, through all the land of Egypt.
So deeply rooted were these insects in the consciousness of Western culture, that the European settlers of America were destined to interpret the Rocky Mountain locust in profoundly religious terms. But making theological sense of such horrendous power was no simple matter—understanding the locust would be as difficult for ministers as it had been for scientists.
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The Sixth Plague
IN THE EYES OF A YOUNG AMERICA, THE FARMER WAS the angel of growth. Thomas Jefferson had idealized the virtues of taming the profligate land and planting gardens in the wilderness. But how could the goodness of agriculture be reconciled with the destruction caused by the locusts? At a deep cultural level, the resolution of this conflict was found in religion. When faced with overwhelming loss, especially when wrought by nature, people often draw upon their faith for comfort and answers. And so, for the nineteenth-century Christian pilgrims battling the forces of nature in the American wilderness, the Bible was a powerful source of insight. However, its message concerning locusts and the suffering that followed the swarms was frustratingly ambiguous.
In ancient times, interpreting the cause of a natural disaster was a vitally important task for theologians. In early cultures, locust swarms were most often understood to be a form of divine punishment, and so t
he most appropriate response was to submit in penitence, pray for forgiveness, and make offerings. According to Pliny, this approach worked in the first century, when appeals to Jupiter produced flocks of rose-colored starlings that destroyed the locusts in Asia Minor. The early Muslims also saw locusts as the apocalyptic agents of God. Even the good Christian entomologists, Kirby and Spence, were well aware of the Islamic perspective: “So well do the Arabians know their power, that they make a locust say to Mahomet, ‘We are the army of the great God; we produced ninety-nine eggs; if the hundred were completed, we should consume the whole earth and all that is in it.’” And in 1864, when American farmers were besieged by locusts, pious Muslims in Syria exorcised and ostracized locusts by reading the Koran aloud in ravaged fields on the other side of the world.
The Christian response to locust invasions was most thoroughly documented in Edward P. Evans’s bizarre and authoritative treatise, The Criminal Prosecution and Capital Punishment of Animals. Amid incredible accounts of legal proceedings against unruly pets and homicidal livestock can be found the strangest of all human-animal legal conflicts that played out in the ecclesiastical courts of Europe—locusts on trial. The earliest involvement of the Church as an extermination agency appears to be in 880, when Roman authorities sought help from Pope Stephan VI. The Holy Father provided a huge volume of holy water, which was apparently used in the course of exorcising the swarm. But exorcism became viewed as a drastic intervention, so a more subtle strategy emerged.
During the reign of Charles the Bold, Duke of Burgundy, the Church took a different tack in dealing with troublesome locusts: excommunication. This approach was applied to a swarm that settled in the northern Italian province of Mantua. In this case, as in many previous instances, the locusts dutifully dispersed not long after the Church’s proclamation. Of course, locust swarms tend to move about even when they are not the subjects of religious persecution, but this entomological pattern did nothing to diminish people’s faith in the efficacy of religious interventions. The use of excommunication, however, raised a thorny theological issue. To be excommunicated one needs to be a communicant in the first place. That is, if an insect is not part of the Church and able to partake in communion, then it is, strictly speaking, nonsensical to excommunicate the creature, no matter how destructive it might be. The only legitimate recourse was to anathematize, or curse, the beasts. But this raised an even more troublesome religious problem.
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