Posts Tagged: chemical ecology
When chemical ecologist Walter Leal, professor of entomology at the University of California, Davis, was elected to the prestigious Brazilian Academy of Sciences, his lab members donned matching t-shirts--t-shirts with a touch of humor and a dose of humility.
On the front: "I did the work."
On the back: "And Walter Leal got in the Academy."
It was his idea and he purchased the t-shirts.
Leal, a native of Brazil, will be honored at a ceremony on May 7 in Rio de Janeiro.
“Let me say that your election to the Brazilian Academy of Sciences is a well-deserved recognition for your accomplishments as a distinguished scientist in your field of studies, entomology, and also for the very important role you have been playing in promoting cooperation among Brazilian and U.S .universities and, through those arrangements, fostering scientific development in our country,” said Ambassador Eduardo Prisco of the Brazilian Consulate in San Francisco.
Leal, a native of Brazil, is a liaison with UC Davis and the Brazil government’s Scientific Mobility Program, launched to exchange graduate and undergraduate students.
The U.S. currently hosts the largest number of students participating in the Brazil government’s Scientific Mobility Program, according to the Institute of International Education, and UC Davis leads the nation, hosting more than 30 Brazilian undergraduate scholarship students. Leal is also involved in the Brazilian/UC Davis student exchange with the Federal Agency for Support and Evaluation of Graduate Education (CAPES) and the National Council for Scientific and Technological Development (CNPq) grants for research related to Brazil.
A pioneer in the field of insect communication and on the cutting edge of research, Leal employs innovative approaches to insect olfaction problems. His work examines how insects detect smells, communicate with their species, detect host and non-host plants, and detect prey. Leal has designed and synthesized complex pheromones from many insects, including scarab beetles, true bugs, longhorn beetles and the citrus leafminer. He and his lab discovered the secret mode of the insect repellent DEET.
Leal, educated in Brazil and Japan, joined the UC Davis Department of Entomology in 2000. He holds a doctorate in applied biochemistry from Tsukuba University, Japan, and also earned degrees in chemical engineering and agricultural chemistry.
You'll be hearing much more of Walter Leal. Active in national and international entomological circles, the UC Davis professor is serving as co-chair of the International Congress of Entomology (ICE) conference, to be hosted by the Entomological Society of America (ESA) Sept. 25-30, 2016 in Orlando, Florida.
His honors and awards are many. He is a Fellow of the ESA, the Royal Entomological Society, and the American Association for the Advancement of Science. He served as president of the International Society of Chemical Ecology (ISCE). Among his awards: the ISCE Silver Medal, and awards from ESA and scientific societies in Japan and Brazil.
Caption (Top Photo):
The Walter Leal lab wore humorous t-shirts to announce his selection to the Brazilian Academy of Sciences. Four countries are represented in this lab photo. The four in front are (from left) Junior Specialist Hang Gao, United States; Professor Fen Zhu, Huazhong Agricultural University, China; Professor Leal, a native of Brazil; and Graduate Student Alyssa De La Rosa (Agricultural and Environmental Chemistry Graduate Group). Circling them in back are (from left) Postdoctoral Fellow Cherre Sade, Brazil; Postdoctoral Fellow Young-Moo Choo, Korea; Project Scientist Pingxi Xu, China; Graduate Student Kevin Cloonan (entomology major), Professor Carlos Ueira Vieira, Federal University of Uberlandia, Brazil; Graduate Student Yinliang Wang, Northeast Normal University, China; and Graduate Student Washington Carvalho, Federal University of Uberlandia.
The Walter Leal lab wearing matching t-shirts. See caption at end of the blog. (Photo by Kathy Keatley Garvey)
Walter Leal (back to camera) talking to his lab members. (Photo by Kathy Keatley Garvey)
Walter Leal isn’t participating in the Olympics, but he medaled just the same.
It was not for athletic prowess, but for scholarly achievements—the scientific equivalent of an international gold medal.
Leal, a chemical ecologist and a professor and former chair of the UC Davis Department of Entomology, is the recipient of the coveted Silver Medal, the highest award given by the International Society of Chemical Ecology (ISCE).
A native of Brazil and educated in Brazil and Japan, Leal researches how insects detect smells and communicate within their species. He is “one of the foremost authorities on the integration of chemical ecology with the molecular, biochemical and physiological interactions among insects and between insects and plants,” said chemical ecologist Coby Schal, professor at North Carolina State University, who nominated him for the award.
Bruce Hammock, UC Davis distinguished professor of entomology, wrote a letter of support, praising Leal for “his outstanding career achievements and excellence in moving chemical ecology forward." Hammock described him as “a world-renowned chemical ecologist, a pioneer in the field of insect olfaction, and on the cutting edge of research.”
ICSE president Paulo H. G. Zarvin of the Federal University of Parana, Brazil announced the award July 26 at the 28th annual ISCE annual meeting, held in Lithuania. It will be presented at the ISCE’s 29th annual meeting, set Aug. 19-22, 2013 in Melbourne, Australia.
Declaring Leal’s program, launched in 1990, as “one of the best in the world,” Schal lauded Leal as “one of the most energetic and collaborative scientists I know.”
“Chemical signaling is fundamental to all life forms, including microbes, plants and animals,” Schal said,” and chemical cues allow animals to appraise their environment; to detect food, toxins, prey, predators and pathogens; to identify kin; and to evaluate and base mate choice decisions of potential reproductive partners.”
“Walter’s research, in two decades, has addressed almost every aspect of chemical ecology,” Schal said. That includes “the semiochemistry of mites, thrips, scarabs, bugs, aphids, cockroaches, moths, wasps and plants.”
Leal, who joined the UC Davis faculty in 2000, has designed and synthesized complex pheromones from many insects, including scarab beetles, true bugs, longhorn beetles and the citrus leafminer. He identified the complex sex pheromone system of the naval orangeworm, a key agricultural pest responsible for multi-million crop damage annually in California. The sex pheromones he discovered are now being deployed in the agricultural field to disrupt chemical communication and control the navel orangeworm population through the environmentally friendly technique of mating disruption.
Leal and his lab discovered DEET’s mode of action, something that had puzzled and eluded scientists for half a century. Scientists long surmised that DEET, patented by the U.S. Army in 1946, works by masking the smell of the host, or jamming the insect’s senses, thus interfering with its ability to locate a host. Not so: in groundbreaking research published in the Proceedings of the National Academy of Sciences (PNAS), the Leal lab found that mosquitoes can indeed smell the chemical repellent but they dislike it so they avoid it.
Leal is one of only 23 scientists to receive the ISCE Silver Medal since its inception in 1986. Two other University of California scientists also won the award: Dave Wood of UC Berkeley in 2001 and Ring Cardé of UC Riverside in 2009.
Chemical ecologist Walter Leal. (Photo by Kathy Keatley Garvey)
Remember the exciting news article published in November of 2009 in Science Daily about how an orchid species on the Chinese island of Hainan "fools its hornet pollinator by issuing a chemical that honey bees use to send an alarm?"
The research was first published in Current Biology, a Cell Press publication.
"The discovery explains why the hornets, which capture honey bees to serve as food for their larvae, have been observed to literally pounce on the rewardless Dendrobium sinense flowers," the Science Daily author wrote.
Can you imagine? Hornets "detect" one of their favorite foods--honey bees--and they pounce on the flower and come up empty-handed or "empty-mouthed?"
The orchids produce a deceptive chemical, a compound called Z-11-eicosen-1-ol, described as "a rarity even in the insect world."
One of the researchers involved in this study--and hundreds of other insect communication studies--is world-renowned chemical ecologist Wittko Francke (top photo) of the University of Hamburg, Germany.
And now he's coming to the University of California, Davis, to present a seminar.
Francke will speak on "Insect Semiochemicals: Structural Principles and Evolution" at a UC Davis Department of Entomology seminar on Wednesday, Dec. 8 from 12:10 to 1 p.m. in 122 Briggs Hall, off Kleiber Hall Drive. He'll be introduced by host and fellow chemical ecologist Steve Seybold of the USDA Forest Service, Pacific Southwest Research Station, Davis, and an affiliate of the UC Davis Department of Entomology."Professor Francke has been a driving force in the field of chemical ecology for the last four decades, discovering countless new natural product chemicals of behavioral significance for animals and helping us to understand how plants and animals interact," said Seybold (left).
"Nearly everyone in the field has collaborated with him at some level; he has been a consummate mentor to younger chemical ecologists and has always been generous with his time, intellect, and chemical skills to everyone in that community," Seybold said. "He is remarkably brilliant in that he sees patterns in the make-up and synthesis of bio-organic compounds that most biologists, and even many chemists, may overlook."
Whew, that stinks!
If you've ever smelled a mosquito gravid trap, you know it's not heaven-scent. This isn’t about the aroma of summer roses or the whiff of freshly baked cinnamon rolls or the fragrance of vanilla-laced skin cream.
No. This is something that stinks to high heaven. Probably low heaven, too.
It’s s-o-o bad (how b-a-d is it?) that you just want to distance yourself from the stench: you hold your nose, mutter “P.U.” and make like a Lightening Bolt (Olympic gold-medal sprinter Usain Bolt).
Said UC Davis chemical ecologist Walter Leal: “It smells like a latrine."
So he and his researchers set out to find a synthetic mixture that attracts mosquitoes but is odorless to humans. And they have. Their mixture, containing the compounds trimethylamine and nonanal in low doses, lures Culex mosquitoes just as effectively as the current gravid trap attractants. But look, ma, no smell!
They did it with what Leal calls "reverse chemical ecology."
The results are published in the current edition of the Public Library of Science Journal or PLOS One.
This research could play a key role in surveillance and control programs for Culex species, which transmit such diseases as
What are gravid traps? They're chemical- and water-infused traps, sometimes called oviposition traps or ovitraps. They're meant to attract blood-fed mosquitoes searching for places to lay their eggs. Scientists monitor these traps to determine the presence of West Nile-infected mosquitoes.
“The gravid traps are more important (than carbon-dioxide traps) for surveillance,” Leal said, “as they capture mosquitoes that have had a blood meal and thus, more opportunity to become infected.”
Leal said that another advantage of the gravid traps is that with the capture of one female mosquito, that eliminates not only her, but hundreds of her would-be offspring. “Each female mosquito has the potential to produce about 200 eggs, and she can have as many as five cycles. So when we capture a gravid mosquito, that can remove as many as 500 females.”
The compounds used in the research, Leal said, are “simple and inexpensive” and would be of great benefit “to not only us but third-world countries where Culex quinquefasciatus is a problem.”
The researchers did preliminary field testing in
Other scientists involved in the study included UC Davis researchers Wei Xu, Yuko Ishida,
(See more information on the UC Davis Department of Entomology Web site)./st1:personname>/st1:personname>/o:p>/st1:place>/st1:country-region>/st1:city>/st1:city>/st1:city>/o:p>/o:p>/st1:place>/o:smarttagtype>/o:smarttagtype>/o:smarttagtype>/o:smarttagtype>
Culex quinquefasciatus laying eggs
Water for mosquito gravid trap