This Day in History: 1926-07-30

Two natural enemies, a bacteria and a wasp, seemed to be restoring the balance of nature against the tent caterpillar pests in the eastern United States according to Dr. Frank E. Lutz, the Ramsey entomologist. Dr. Lutz was the director of the Station for the Study of Insects established by the American Museum of Natural History in Harriman State Park. Dr. Lutz had been conducting a series of experiments in an old barn made available for his use by W. Averell Harriman, one of the Commissioners of the Palisades Interstate Park Commission. Lutz was trying to find out how female tent caterpillars select mostly wild cherry trees to build their nests. Since they did it at night, sight was not a factor, he concluded. Their mouths were not equipped for tasting and hearing was out of the question, so that left only touch and smell among the familiar five senses. He rigged an experiment using oak twigs and cherry leaves, and cherry twigs and oak leaves to see which the caterpillar would use to lay their eggs. The experiment failed, since only one batch of eggs was laid. When the insects were analyzed they were found to be sick with a bacteria. Further investigation showed that many of the tent caterpillars in the park that year were too sick to change into moths. Also a species of wasp was preying on the cocoons. Dr. Lutz’ conclusion was that in offering school children prizes for burning nests we might be eliminating also the natural restraints on the expansion of the pests. The Field station was best known for establishing labelled nature trails in Harriman Park so that visitors could better understand the natural area. (Bristow)