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| Chemical ecologist Walter Leal working in his lab. (Photo by Kathy Keatley Garvey) |
DAVIS--Chemical ecologist Walter Leal, professor of entomology at the University of California, Davis, is profiled in today's "Member Spotlight" on the American Association for the Advancement of Science (AAAS) website.
Leal, elected a Fellow of AAAS in 2006, is the second UC Davis Department of Entomology faculty member featured by AAAS this year. Professor James R. Carey drew headlines in a NewsFocus piece on "From Medfly to Moth: Raising a Buzz of Dissent," in the Jan. 8, 2010 edition of Science, published by AAAS.
Freelance journalist Carrie Peyton Dahlberg, formerly with the Sacramento Bee, lead the Leal story with:
" Even when he settles into his office, Walter Leal is unstoppable. Into an already compact space, Leal has crammed a stationary bicycle, so he can keep moving while reading research papers. He likes to compare his time on the bike to writing grant proposals. You work and work, he says, and get nowhere.
" When Leal works and works, though, he usually gets somewhere."
Peyton Dahlberg went on to say that Leal "tries to understand at the molecular level exactly what an insect is smelling, and how it relies on scent to interact with the world."
Her article included a quote from Leal's colleague, John Hildebrand, a neurobiology professor at the University of Arizona, Tucson:
“He’s one of the most dynamic people in the field. He’s a remarkably energetic and passionate person about his work … and notorious almost for the rapid fire way he speaks. He loves to joke that he can say twice as much in a lecture as anyone else because he only says half of each word.”
It was the Leal lab that discovered the secret mode of DEET. The groundbreaking research proved that “DEET doesn’t mask the smell of the host or jam the insect’s senses," Leal said in a UC Davis Department of Entomology news story. "Mosquitoes don’t like it because it smells bad to them.”
DEET’s mode of action or how it works puzzled scientists for more than 50 years. The chemical insect repellent, developed by scientists at the U.S. Department of Agriculture and patented by the U.S. Army in 1946, is considered the "gold standard" of insect repellents worldwide. Worldwide, more than 200 million use DEET to ward off vectorborne diseases.
Scientists long surmised, incorrectly, that DEET masks the smell of the host, or jams or corrupts the insect’s senses, interfering with its ability to locate a host. Mosquitoes and other blood-feeding insects find their hosts by body heat, skin odors, carbon dioxide (breath), or visual stimuli. Females need a blood meal to develop their eggs.
In her article, Peyton Dahlberg said Leal is trying to find something better than DEET.
Wrote Peyton Dahlberg: "DEET is a flawed tool, a chemical that needs to be used at high doses, can affect human biology, and isn’t recommended for very young infants, according to Leal and others who have studied it. The point is finding something better than DEET, something more targeted to the most problematic insects and less dangerous for everything else, including people."
Leal told her that that to search for safer alternatives to DEET and other insecticides, researchers need to better understand the mechanisms of scent detection and chemical communication.
AAAS is the world's largest general scientific society, and publisher of the journal, Science. Founded in 1848 to "advance science and serve society," AAAS serves some 262 affiliated societies and academies of science, including 10 million individuals.
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
