Walter Leal Praises 'Bee Team' During His Faculty Distinguished Research Award Lecture

“Just like in a honey bee colony, it takes a team to win an award.”

So commented UC Davis distinguished professor Walter Leal, recipient of the UC Davis Academic Senate’s 2024 Faculty Distinguished Research Award, when he delivered his seminar at the Academic Senate’s recent research award lecture luncheon in the UC Davis Conference Center.

Leal chronicled his career, detailed his research, and singled out family, friends, students, and colleagues--including UC Davis Department of Entomology and Nematology faculty and staff—who each played a role leading to the award. 

Leal, a member of the Department of Molecular and Cellular Biology faculty since 2013, and former professor and chair of the Department of Entomology, is the first UC Davis faculty member to win Academic Senate’s trifecta of coveted awards: Distinguished Teaching Award for Undergraduate Teaching (2020), Distinguished Scholarly Public Service Award (2022) and now, the Faculty Distinguished Research Award. A week before the seminar, Leal was elected to the National Academy of Sciences.

“Dr. Leal is an internationally recognized entomologist and a world leader in his field for his groundbreaking and transformative research in insect olfaction and chemical ecology,” said  UC Davis distinguished professor Bruce Hammock, who nominated Leal for the Faculty Distinguished Research Award.  

Leal credits Hammock, a 25-year friend and colleague, as instrumental in “luring” him from his tenured position in the Ministry of Agriculture, Forestry, and Fisheries, Japan, to the Department of Entomology (now the Department of Entomology and Nematology) in 2000. A native of Brazil, Leal received his Ph.D. in applied biochemistry from the University of Tsukuba, Japan, with subsequent postdoctoral training in entomology and chemical ecology at the National Institute of Sericultural and Entomological Science and Cornell University, respectively. 

 “He is truly a renaissance man,” Hammock wrote in his nomination letter. “He chaired our entomology department from 2006 to 2008, and under his tenure, our department was ranked No. 1 in the country. I’ve long admired (1) his rigorous fundamental research programs supported by National Science Foundation, National Institutes of Health, and the U.S. Department of Food and Agriculture, and other agencies, (2) how he tackles and solves multiple challenging problems in insect olfaction and chemical ecology, (3) his grasp of how to organize and moderate highly successful worldwide research webinars (4) his generosity in helping other succeed and (4) his finely honed sense of humor. In his basic-to-applied science research, Dr. Leal solves entomological problems spanning agriculture, human health, and welfare. For example, he translates pheromone technology to agriculturists and serves as a principal investigator for the  Pacific Southwest Regional Center of Excellence for Vector-Borne Diseases (affiliated with the Centers for Disease Control and Prevention).  He holds more than 20 patents.”

“Walter has been exceptionally conscientious, active, and generous in professional service at UC Davis,” Hammock pointed out. “In August of 2021, he achieved a ‘first’ for international science communication when he organized and led the extraordinary virtual conference ‘Insect Olfaction and Taste in 24 Hours Around the Globe.’ I especially applaud him for elucidating the mode of action of the insect repellent DEET, developed in 1946 and known as ‘the gold standard of repellents.’ Its mode of action remained an enigma for six decades until Walter’s discovery. In researching the neurons in mosquito antennae sensitive to DEET, he isolated the first DEET-sensitive odorant receptor, paving the way for the development of better repellents.”

Hammock also called attention to Leal’s odorant receptor work involved in the reception of mosquito oviposition attractants, and his work unveiling a circadian rhythm of sex pheromone reception in a scarab beetle.

'Thanks For Coming, Thanks for Staying'

Leal began his seminar by quipping: “Thank you all for coming, and I hope at the end of the presentation I can also thank you for staying.”

“Typically, at the end of the presentation, the speaker acknowledges people who contribute to their research,” Leal said. He chose to list them first.

They included his family, wife Beatriz; sons Augusto and Gabriel; and daughter Helena. Gabriel and Helena, now adults,  worked in his lab as youths and published research papers.

One project involved Helena,  honey bees and her shampoo. “Helena always said the bees were bothering her and then when we collected the volatiles from her, we noticed that there was a contaminant, isoamyl acetate,” Leal told the crowd. “To make a long story short, isoamyl acetate is a chemical that elicits a very aggressive behavior. It’s called a sting pheromone known from the early 1960s, and we figured out that that chemical was coming from a shampoo that she was using at that time--the so-called Aussie.  So, she stopped using that shampoo and there was no problem with the bees anymore.”

Leal thanked the National Institutes of Health (NIH) and the NIH National Institute of Allergy and Infectious Diseases for their continuous financial support and the more recent funding from the Centers for Disease Control and Prevention “under the leadership of UC Davis professor Chris Barker in the PacVec program (Pacific Southwest Center of Excellence in Vector-Borne Diseases.” Leal has also drawn funds from the National Science Foundation, USDA from the FUNDECITRUS, Bedoukian Bio Sustainable Pest Management, almonds and pistachio boards, and various donors.

Tribute to Scientists 

In his seminar, Leal paid tribute to his students, postdoctoral scholars, research scientists and collaborators. He opened his entomology lab on April 1, 2000. “I named the lab not after my family name which is a convention here but after two colleagues from entomology Susumu Maeda and Sean Duffey so the lab was called the Maeda-Duffey while I was in entomology.”

Among those he singled out were a number of faculty and staff with the UC Davis Department of Entomology and Nematology: 

• Richard "Dick" Rice (1937-2011), a UC Davis professor who worked at the Kearney Agricultural Research and Extension Center for 33 years. He was the “anonymous donor” who contributed $30,000 toward “my startup.” 
• Bruce Hammock, “who came all the way to Japan to Tsukuba and he came to my lab to try to convince me that I should apply for a position at UC Davis. Another is Paul Gepts who was then the chair of the Department of Agronomy and Range Science.”
• Frank Zalom, now a UC Davis distinguished professor emeritus on recall.  “We did a lot of work in agricultural pests, including the navel orangeworm, a pest of almonds and other crops.  “If you want to do anything in entomology that's important for agriculture you have to go talk to Frank Zalom.”  Leal discovered a pheromone that “saved California agriculture millions of dollars.”  
• Leal lab alumni Kevin Cloonan, now a USDA research entomologist, and Wei Xu, now an insect biologist at Murdoch University, Australia.
• Leal lab postdoctoral researcher and chemical ecologist Zain Syed, now on the University of Kentucky faculty
• Kathy Keatley Garvey, communications specialist, UC Davis Department of Entomology and Nematology and systems administrator Hemang Patel of the Department of Molecular and Cellular Biology, for their assistance. 

Leal discussed his mosquito research and asked the audience if they knew that a species of mosquito, Anopheles freeborni, a vector of malaria, is named for UC Davis Chancellor Stanley Freeborn (1891-1969). Freeborn, the first UC Davis chancellor, was a medical entomologist.

“We had many, many wonderful collaborators in postdoc in the lab,” Leal said. “One of them was Zain Syed.” The Leal lab’s groundbreaking discovery of the mode of action of DEET, resulted in widespread coverage in scientific journals and in the mainstream media, including the New York Times. 

“Most insects respond to DEET, even cockroaches…one insect that does not respond to this is Rhodnius prolyxus (which) that carries the Chagas disease…so in accidentally looking for a pheromone receptor, we found the receptors for compounds that are repellents for Rhodnius.”

In closing, Leal showed an aphorism (“Illeqitimii non-carborundum,” a joke or fake Latin phrase) on his office door that the late entomology professor, Charlie Judson (1926-2015), gave him “when I arrived here, and said you might need this. Perhaps it's working.” The aphorism, originating in World War II, generally means “Don’t let others grind you down.” 

Leal ended with: “I hope that I convince you that the work performed by the cast of thousands deserve the distinguished research award.”

See his video at https://youtu.be/HkfhsYQE5bI.

UC Davis distinguished professor Pamela Ronald, also a recipient of a 2024 Faculty Distinguished Research Award, delivered a seminar, “Engineering Crops for Resilience to a Changing Climate.”  She holds a joint appointment with the Department of Plant Pathology and the Genome Center. Like Leal, she is a member of the National Academy of Sciences. See her video at https://video.ucdavis.edu/media/2024-05-07_Faculty-Research-Award-Luncheon/1_s36f3s4w.