Robert Whitcomb; entomologist explored the microbial world

WASHINGTON - Robert Franklin Whitcomb, 75, a research entomologist at the Beltsville (Md.) Agricultural Research Center who identified more than 50 new species of leafhoppers and about 60 new species of microorganisms, died of brain cancer Dec. 21 at Hacienda Rehabilitation and Care Center in Sierra Vista, Ariz. He lived in Sonoita, Ariz.

Mr. Whitcomb was known worldwide for his 1972 discovery of the genus Spiroplasma, a group of mollicutes, or small bacteria without cell walls. He worked on these microorganisms for the rest of his career.

"The world is essentially a microbial world," he wrote in a 1989 paper. "Although we may pretend to be eukaryotes, we are impostors. . . . Spiroplasma, although discovered a mere 17 years ago, may be the largest genus of any kind on earth and may contain more than a million species."

He also was deeply interested in birds, and one of his articles, which applied the ideas of island biogeography to mainland bird populations in the eastern deciduous forest, was considered a landmark study. It led to the current emphasis on the negative effects of forest fragmentation on biota, or all the living organisms of the forest.

On the Agriculture Department's Beltsville campus, Mr. Whitcomb was widely credited with the successful re-creation of its grasslands, a unique landscape in the Washington area that contains the progeny of plants seeded in Colonial times or before. More than 234 species live in the uncut meadowland, he told a Washington Post reporter in 1997, and it's managed naturally.

Few might expect a natural scientist to be born in New York City, as Whitcomb was. He graduated from Blackburn College in Carlinville, Ill., and received a master's degree in entomology in 1958 and a doctorate in plant pathology in 1961, both from the University of Illinois. He did postdoctoral work in entomology at the University of California at Berkeley for five years. He moved to the Washington, D.C., area in 1966 to work at Beltsville, where he remained for the next 30 years.

He was an original member of the International Organization for Mycoplasmology in 1974 and taught one of its methods courses in Bordeaux, France, in 1984. He received the group's highest honor, the Kleineberger-Nobel award, in 1994. He published more than 300 scientific papers and in 1979 was one of four editors of a new series of scientific reference books, "The Mycoplasmas."