An entomological who dunnit

Jeff Lockwood's book, Locust: The Devastating Rise and Mysterious Disappearance of the Insect That Shaped the American Frontier is available on Amazon, where I reviewed it.

Scientific understanding usually shuffles along in the two-to-three-year steps of graduate student research projects. Big, intriguing mysteries take longer to resolve, but are more fun to research—and more interesting to read about.

Jeff Lockwood tackled the mystery of why the Rocky Mountain locust went extinct at the dawn of the 20th century. The species' periodic irruptions rivaled the bison in terms of biomass and the 1875 outbreak still horrifies young readers of Laura Ingles Wilder's, On the Banks of Plum Creek. Then the insects disappeared.

In his book, Lockwood recounts the challenges of sleuthing out a big mystery. Big research projects require new research techniques and years of soul-crushing work counting, dissecting, measuring, and recording data. Papers describing new research findings are sometimes rejected by academic journals; colleagues sometimes snicker. Unearthing the Rocky Mountain locust's secrets required field work at remote high elevation "grasshopper glaciers" reached by difficult climbs in foul weather.

Big research projects need lots of brains and lots of backs. Lockwood doesn't hog the limelight; he credits his employees, students, and colleagues for their inventions and insights. Field research is carried out by people, so it's a social activity, which Lockwood captures. A twenty-five-mile hike, completed in the dark, isn't quite as bad when you're not suffering alone, and joy shared at discovery is joy multiplied.

Other ecological changes in the late 19th century might have been linked with the locust's disappearance: decline of the bison, changes in climate, or reduced burning by Native Americans. Lockwood guides readers through the possibilities and explains why he rejects each. He focuses instead on the ecological bottleneck of limited egg-laying sites in valleys of the northern Rocky Mountains. Lockwood determines that when settlers plowed and grazed these areas, they destroyed the locust's eggs, and with them, the species. The culprit was settlers, in valleys, with plows, by accident.

Although the Rocky Mountain locust's sky-filling swarms are gone with the thundering bison herds, Lockwood ends his book by wondering if a few individuals may live incognito in less disturbed valleys of the Rockies. Another big, intriguing mystery.