He shed light on glowing insects; Expert: Dr. William D. McElroy, the 'firefly man,' was no flash in the pan -- his research illuminated scientists for decades.

In the late 1940s and 1950s, the serenity of a humid Maryland summer's night was most likely to be disturbed by platoons of net-carrying youngsters trooping over yards and fields, swooping up lightning bugs by the thousands.

The tiny, graceful creatures, with their soft luminous flashings that filled the night, were as much a part of summer evenings in those years as the jingling bells of the Good Humor man, the endless hum of window fans or front porches that were illuminated by the glow from yellow light bulbs.


The bounty from these hunting expeditions were taken and sold to Dr. William D. McElroy, professor and later chairman of the biology department at Johns Hopkins University, who was conducting research into the nature of the insect's flash.

McElroy, who left Hopkins in 1969 when he was nominated to head the National Science Foundation and later became chancellor of the University of California at San Diego, died in February.


A leading authority on bioluminescence, it was McElroy who discovered that the flash was the result of an enzymatic reaction with the compound ATP, or adenosine triphosphate.

McElroy, who was world-renowned for his discovery, remained a much sought after authority on the flashing bugs until his death.

"This was a period of basic science," J. Woodland Hastings, a Harvard biologist who worked with McElroy, told the New York Times at the time of his death.

Because fireflies or lightning bugs were an obvious example of bioluminescence, little was known about them.

"They were not only an example, but a leading example, and they were available, especially in Baltimore," Hastings said.

The first gathering was organized in 1947, and to stimulate his huntsmen, McElroy offered a bounty of 25 cents for every 100 fireflies that were delivered to Room 113, Mergenthaler Hall, on the Johns Hopkins Homewood Campus.

To further spur on the hunt, McElroy offered a $10 prize to the person who sent in the most fireflies.

"Life in Baltimore, for the fireflies, became a chancy, precious thing. ... The result of this was a mass attack on the firefly population in Baltimore and indeed, in such outlandish places as Long Island, N.Y.; Ohio, Pennsylvania and Delaware. A newspaper in Indianapolis offered to alert the youth of Indiana," reported the Evening Sun.


At the end of the first "season," which ranged from late June until mid-August, Morgan Buchner Jr., 10, of Hadley Square in Guilford, had won the $10 prize and McElroy had 40,000 donated fireflies from all contributors safely stowed in his laboratory -- frozen for later experiments or immediately dissected.

In good years, Baltimore's youths netted as many as 500,000 lightning bugs. Supplies of the flashing bugs eventually reached 1,000,000 a year by the 1960s, thus arousing fears that one of the area's symbols of summer might disappear.

"Some people have complained that our collections might cut deeply into the firefly population, but the flies we are collecting are males," McElroy told The Sun in a 1965 interview. "The females stay in the grass and lay eggs; so our collection should have no effect on the population."

At the time of his death, the New York Times described his work this way: "Dr. McElroy has made valuable contributions to science, including the discovery that the process by which some creatures make their own natural light is closely related to the process by which all animals convert chemical energy into mechanical energy."

But in a 1977 interview, the scientist who became known as the "firefly man" said it better: "Quite frankly, that was the most fun I ever had in my life."

Pub Date: 6/12/99