UNIVERSITY PARK, Pa. — Penn State's Department of Entomology, the College of Agricultural Sciences and the University community are mourning the loss of James H. Tumlinson, Ralph O. Mumma Professor of Entomology, who died Feb. 9 at the age of 83 after an extended illness.
Tumlinson was an internationally respected researcher and mentor in the interdisciplinary field of chemical ecology, which deals with the chemical signals that help control interactions among living things. His research focused on chemicals that affect insect behavior, plant-insect interactions, plant signaling and plant defenses, with an emphasis on developing fundamental knowledge that can be applied in environmentally safe pest-management programs.
"Jim was a friend and colleague with whom I had the great pleasure of collaborating during his time at Penn State," said fellow chemical ecologist Gary Felton, professor and head of entomology. "Jim's contributions to the science of chemical ecology are groundbreaking, with great impact on agriculture. From his early work on the identification of pheromones of major insect pests, such as the boll weevil, to later developing the concept of indirect plant defenses, Jim remained a tour de force throughout his long career with the USDA and with Penn State."
A native of Mississippi, Tumlinson earned a bachelor's degree in chemistry from Virginia Military Institute in 1960 and master's and doctoral degrees in organic chemistry from Mississippi State University in 1966 and 1969, respectively. After a year as a postdoctoral fellow at the New York State College of Forestry, he joined the U.S. Department of Agriculture's Agricultural Research Service in Gainesville, Florida, where he was a research chemist and then research leader for more than 30 years in the Center for Medical, Agricultural and Veterinary Entomology.
Early in his research career, Tumlinson discovered and synthesized the sex pheromone of the boll weevil, a destructive pest of cotton in the southern United States. As a result of his work, the pheromone became a key component of an eradication program that had an enormous positive impact on the cotton industry and state economies in cotton-growing regions.
Later, his work in this area earned him the USDA Secretary's Award for Personal and Professional Excellence "for pioneering research on insect pheromones that provided the basis for control of major insect pests, including the boll weevil, thereby reducing environmental contamination by pesticides."
In 2003, Tumlinson joined the Penn State entomology faculty as a founding member of the Penn State Center for Chemical Ecology, which he led from 2006 until the time of his death. Some of his recent research examined the interactions among herbivorous insects, their host plants and their natural enemies. Among his findings were that plants damaged by insect feeding synthesize and release volatile organic chemicals that attract small wasps, which locate and parasitize the caterpillars, and that these chemical defenses of the plant are induced by compounds in the oral secretion of the caterpillars.
His lab also identified volatile compounds emitted by plants in response to infections by pathogens, including bacteria and fungi, and discovered mechanisms by which plants can detect and report pathogens.
Tumlinson's research brought him international acclaim. In 2008, he and two other scientists shared the Wolf Prize in Agriculture, regarded by some as the agricultural equivalent of a Nobel Prize. The Wolf Foundation said the researchers "have been a major force in reorienting the thinking of agricultural scientists and educators toward a more ecologically sound approach to pest management.
"Their research has demonstrated the sophisticated natural system of biological interaction between plants, insects feeding on plants, and predators and parasitoids of these herbivores," the foundation added. "(Their) impressive contributions … in developing and applying scientific understanding have shifted the pest management agenda worldwide."
Upon receiving the Wolf Prize, Tumlinson characteristically deflected credit to others. "The research recognized by this award was conducted over at least three decades by numerous really excellent students and research associates, and in collaboration with Joe Lewis, a co-recipient of this prize, and other colleagues," he said at the time. "It has been an interdisciplinary team effort. No one person or laboratory alone could have accomplished this."
The author or co-author of nearly 300 scientific papers in peer-reviewed journals, Tumlinson was elected to the National Academy of Sciences and as a fellow of the Entomological Society of America. He was a member of, and received many awards from, other professional organizations, such as the International Society of Chemical Ecology, for which he served as president, and the American Chemical Society.
Although Tumlinson's career focus was primarily research, he also was a dedicated teacher and mentor. Ted Turlings, a professor of chemical ecology at the University of Neuchâtel in Switzerland, studied under Tumlinson for eight years as a doctoral candidate and postdoctoral scholar at the USDA-ARS lab in Gainesville, Florida.
"I first became aware of Jim’s work when I was a master’s student at the University of Leiden in The Netherlands," Turlings said. "His work on parasitoids conducted in collaboration with Joe Lewis is what attracted me to his research group."
Turlings called Tumlinson "one of the founding fathers" of the field of chemical ecology. "He was among the very best, initially as one of the pioneers in the very challenging field of identifying the sex pheromones of agriculture pests, and later as one of the first to apply chemical ecology to multitrophic interactions. He had a great feeling for what would or should be the next research trend. In that sense, he was often a step ahead of others."
Turlings credits Tumlinson for guiding his own research philosophy. "Research was his passion, which rubbed off on me and others who worked with him," he explained. "He took pride in being meticulous and getting things absolutely right, even if it took years. This drive to publish only if he was fully convinced of the results is what I hope to have inherited and practice in my own research. He was a true leader, occasionally tough, but always fair and never unreasonable.
"I hope that Jim’s ethics and style of conducting research will be an inspiration for others as it has been for me."
Tumlinson's dedication to his mentees was apparent to the end, noted Felton.
"Jim's recent emails and last phone call with me centered not on his declining health, but instead were focused on wanting to ensure that his students were taken care of," he said.