Book Review: Locust

By Jeffrey Alan Lockwood
Reviewed by Jonathan Beard

Locust begins on the newly settled Nebraska prairies in1875. For thousands of families between 1874 and 1876, an ordinary summer day would suddenly turn catastrophic as the skies turned yellow, then began to rain locusts by the million. They lost their crops and even the handles of their tools to the clouds of famished insects. The massive outbreaks killed some settlers through starvation and drove thousands to despair. Because plagues of locusts threatened the settlement of the plains, the U.S. Congress established an “Entomological Commission” to find a solution. Lockwood marks this as the beginning of government-funded research on insects in the U.S. The commission published a massive report, while inventors devised machines to crush or burn the billions of locusts.

But it was all needless work. The swarms of migratory locusts, which had swept over central North America for centuries, were gone. There would be local outbreaks, but Melanoplus spretus was extinct.

This beautifully written book tells three stories: that of the American agricultural frontier and locust plagues; the growth of economic entomology and our understanding of the locust; and the riddle of the sudden extinction of a massively abundant species. For conservationists, Lockwood draws parallels between the fate of the tallgrass prairie and its two dominant herbivores, the buffalo and the locust.

Lockwood began unraveling the mystery of the Rocky Mountain locust while working on grasshoppers at the University of Wyoming. Where was the “permanent zone” where it bred quietly between outbreaks? Did it sicken and decline, or die out suddenly? Was Melanoplus spretus truly a separate species, or was it perhaps the migratory phase of a grasshopper species still extant in North America? And, finally, why did it go extinct?

The solution involved arduous climbing into Wyoming’s mountain glaciers, culminating in the discovery of ice layers that had trapped swarms of locusts over centuries. Dissection and chemical analysis of frozen locusts enabled him to determine that Melanoplus spretus had indeed died out even as it flourished, and that it was a separate species. This information, together with years of reading and discussions with colleagues, led Lockwood to a solution. The locusts’ permanent zone had been a handful of green mountain valleys settled by miners and farmers at the same time as the vast plains. Destruction of these reservoirs had led to extinction. It had been quick—just as a few loggers in Mexico could in hours destroy the Monarch butterfly by eliminating its overwintering grounds.

Settlement of the plains and mountains removed both keystone herbivores—bison and locusts—just as it destroyed the tallgrass prairie. The millions of bison and billions of locusts that shaped the grasslands and recycled its carbon are gone—as are the Indians who lived there and consumed both. Wheatfields and cattle have replaced that ecosystem. At the end, Lockwood examines some grasshoppers in Yellow-stone National Park, the only area in the “permanent zone” which escaped the plow. Conceivably, they are Melanoplus spretus. Could anyone (such as a specialist in controlling grasshoppers on Wyoming rangeland) conceive of reintroducing this species?


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