Kinsey's Other Report

Natural History, July, 1999 by Michael Yudell

Of the nearly 18 million insects in the Museum's entomological collections, more than 5 million are gall wasps that were collected by Alfred C. Kinsey. Most remember Kinsey for his groundbreaking studies in human sexuality (commonly known as the Kinsey reports), published in 1948 and 1953. But prior to becoming the doyen of American sexologists, Alfred Kinsey had a distinguished career as an entomologist.

After receiving his Ph.D. in biology from Harvard in 1919, Kinsey quickly established himself as one of the leading entomologists of his time, specializing in gall wasps (Cynipidae)--tiny plant-eating members of the order Hymenoptera. Although at most only eight millimeters long, gall wasps look threatening under a microscope, plated with natural armor as if ready to head off into battle. Their coarse bodies are lined with tiny hairlike structures, and they have four delicate-looking wings.

Gall wasps are distinguished from other wasp species by the galls they create, which are in effect external reproductive structures. Think of them as you would a chicken's egg, except that a gall is created when a female gall wasp deposits her egg on"to the leaf or stem of a host plant (see "Just Lookin' for a Home," Natural History, September 1998). A biochemical reaction between the egg and the host produces the gall, inside of which the growing larvae are nourished. Found mainly on roses and oaks (but also on blackberries and goldenrods), galls vary in shape and size from species to species. Some of them measure just a few millimeters in length and look like dots on the leaves of oaks. Others are larger and more elaborate, growing up to several centimeters in diameter and having a fuzzy, almost hairlike surface. Still others have a spiked surface.

Approximately three thousand species of gall wasps are found worldwide, but Kinsey worked with only the five hundred or so North American and Central American species. Kinsey was an avid, if not an obsessive, collector. During a yearlong postdoctoral fellowship beginning in 1919, he traversed some thirty-six states and, in the process, logged more than 18,000 miles (2,500 of them on foot). Later in his career, Kinsey even modified a half-ton truck to facilitate his back-road collecting trips--a kind of one-man traveling show. His graduate students playfully referred to the truck as Kinsey's juggernaut. In his laboratory, where he reared the majority of his specimens (which had been brought into the lab, unhatched, in their galls), Kinsey recorded twenty-eight different measurements for each wasp. Individuals were glued to a tag attached to a pinhead. Painstakingly inscribed on each tiny tag were the species name and the date and location of collection.

As early as 1922, the twenty-eight-year-old Kinsey, looking to secure his relationship with the American Museum of Natural History (which had already published parts of his doctoral work), promised the Museum his entire collection. The first donation came that same year and contained, by Kinsey's account, sixty-six new species of gall wasps and their galls. For this Kinsey was paid approximately $400 and made a life member of the Museum. The bulk of the collection arrived in 1958, two years after Kinsey's death, and was valued at $250,000. William Morton Wheeler, a renowned Harvard entomologist who was Kinsey's mentor during his graduate-student days, may have been responsible for his Museum association, since Wheeler was a curator in the Department of Entomology from 1903 to 1908 and a Museum research associate until his death, in 1937.

Kinsey's work on gall wasps laid the groundwork for his later studies of human sexuality. Stephen Jay Gould pointed out in "Of Wasps and WASPs" ("This View of Life," Natural History, December 1982) that "the special character of Kinsey's work ... flowed directly from the taxonomic approach he had learned and perfected as an entomologist." As a taxonomist, Kinsey was concerned with studying and quantifying variety in nature, and this approach meant that his samples were large and diverse. Kinsey could therefore conclude "as wasps varied from [evolutionary] tree to tree, classes, sexes, and generations might differ widely in their sexual behavior."

Kinsey's collection, after all these years, is finally getting the careful attention it deserves. Gall wasp specialist Zhiwei Liu--a postdoctoral fellow in the Museum's Department of Entomology who is now working his way through Kinsey's enormous and invaluable collection--is the first scientist to study the wasps in depth. Liu is particularly interested in inquiline species--those that raid galls produced by other gall wasp species. Thanks to the collection's extraordinary scope, the Museum's preservation skills, and Liu's hard work, Kinsey's wasps have, after years of dormancy, come to life once again.

Michael Yudell is a Ph.D. candidate in history at the Graduate' Center, City University of New York. He is also a research fellow in the Molecular Systematics Laboratory at the American Museum of Natural History.