While fossil evidence shows that the voracious Rocky Mountain locust was rampant in what is now North America as early as the 12th century, it didn't reach its peak of collective destructiveness there until the 1870s. Miles-long clouds of the insects blanketed the territory between the Mississippi River and the Rocky Mountains by then, destroying untold acres of crops and bringing tens of thousands of settlers to the brink of starvation. By the dawn of the 20th century, however, the dreaded marauder had become extinct. Jeffrey Lockwood, a professor of natural sciences and humanities at the University of Wyoming, describes the locust's impact on American agriculture, science and social policy, and chronicles his own discovery of how the species died off so quickly in the wide-ranging book Locust: The Devastating Rise and Mysterious Disappearance of the Insect that Shaped the American Frontier.
At the height of their depredations, the locusts swept in like summer storms. "They came rattling and pattering on the houses, and against the windows, falling in the fields, on the prairies and in the waters everywhere and on everything," wrote a Kansas observer, who told of an invasion of his land that began at one in the afternoon. "By about 4 o'clock," he continued, "every tree and bush, buildings, fences, fields, roads, and everything, except animated beings, was completed covered." Once on the ground, these creatures would reduce flourishing cornfields "into a desolate stretch of bare, spindling stalks and stubs."The devastation was so widespread, Lockwood reports, that local communities could not provide sufficient relief. The state and national governments had to intervene, thus beginning a pattern of farm assistance that continues to this day. Then, as now, some politicians were reluctant to offer help, not for budgetary limitations only but because they thought charity would lead to moral corrosion and dependence. While the state governments argued the pros and cons of relief, they also called for official days of prayer, seeing in the disasters echoes of the biblical plagues. Some of the forward-looking states hired scientists to apply reason to the problem. In the meantime, entrepreneurs poured forth a tide of machines and potions, all designed to obliterate the invaders, but none of which proved very effective. Although he touches on all these side effects, Lockwood concentrates on profiling the major entomologists who took on the locusts and assessing their findings, theories and achievements.
After it became apparent that the Rocky Mountain locust was either extinct or monumentally dormant, scientists undertook to find the cause. Some thought it could be explained by the introduction of alfalfa crops (not a locust favorite). Others argued that it proceeded from changes in weather patterns or the decimation of the buffalo herds. But Lockwood, taking his cue from the fate of the monarch butterflies, whose regeneration zone in Mexico is rapidly being destroyed, contends that it was the settlers' cultivation of the high fields in the Rocky Mountain river valleys, where the locusts retreated between invasions, that ultimately did in these ravenous creatures.
In spite of the complexity of his subject, Lockwood relates his story with simplicity and humor. Readers with an interest in science and history particularly that of the frontier will enjoy this well-told entomological mystery. Edward Morris reviews from Nashville.