- Walter Leal, distinguished professor, Department of Molecular and Cellular Biology and former chair of the Department of Entomology (now the Department of Entomology and Nematology
- Cristina Davis, the Warren and Leta Geidt Endowed Professor and Chair, Department of Mechanical and Aerospace Engineering
NIA honors and encourages academic inventions that benefit society. Between the two UC Davis faculty members, they hold 42 patents: Davis with 12; and Leal with 28 Japanese and 2 U.S. patents.
Davis is a world leader in trace chemical sensing, while Leal is a leading global scientist in the field of insect olfaction and communication, investigating how insects detect odors, how they detect host and nonhost plant matter, and how they communicate within their species.
Leal's research, spanning three decades, focuses on insects that carry mosquito-borne diseases as well as agricultural pests, such as the Asian citrus psyllid and the orange navelworm. He and his lab drew international attention with their discovery of the mode of action of DEET, the gold standard of insect repellents.
We remember when Leal and a group of 18 students hosted a Zika Public Awareness Symposium in 2016 on the UC Davis campus. It was an amazing symposium that drew attention to Aedes aeqytpi, which transmits the disease. Soon thereafter, Brazilian-born Leal and his colleagues in Brazil, detected the Zika virus in wild-caught Culex quinquefasciatus mosquitoes in Recife, the epicenter of the Zika epidemic.
We also remember when Leal identified the sex pheromones of the navel orangeworm (Amyelois transitella), a pest of almonds, figs, pomegranates and walnuts, the major hosts. This led to practical applications of pest management techniques in the fields.
Those are just several examples of the work he does. And still, he found time to co-chair the 2016 International Congress of Entomology meeting, "Entomology Without Borders," in Orlando, Fla., that drew the largest delegation of scientists and experts in the history of the discipline: 6682 attendees from 102 countries.
We're not sure how Leal can find the time to do all this (see news story on the UC Davis Department of Entomology and Nematology). We figure he must have a clone! Make that multiple clones!
At any rate, Leal is the second faculty member affiliated with the entomology department to be selected an NIA fellow. The other scientist: Bruce Hammock, distinguished professor, who holds a joint appointment in the Department of Entomology and Nematology and the UC Davis Comprehensive Cancer Center. Hammock is the co-founder and chief executive officer of EicOsis LLC, a Davis-based company that is developing a non-opiate drug to relieve inflammatory pain in companion animals and target chronic neuropathic pain in humans and horses.
As Hammock said: “When Walter Leal reached UC Davis (in 2000), he came with the reputation of being a 'one man army in research.' This reputation was well deserved. I know of no one at UC Davis who matches Walter in taking his remarkable fundamental advances in science and translating them to increase the safety and magnitude of world food production.”
Jordan, the second-highest-scoring NBA player scorer (5,987 points), "wasn't good enough" to make his high school varsity basketball team (at first). And the late Tom Eisner, the renowned Cornell University professor who went on to be known as "the father of chemical ecology," just "wasn't good enough" to be accepted at Cornell as an undergraduate student.
"Sorry, you didn't make it!" probably rang in their ears.
So when chemical ecologist and distinguished professor Walter Leal of the University of California, Davis, delivers the Founders' Memorial Award Lecture on Tom Eisner (1929-2011) at the Nov. 17-20 Entomological Society of America (ESA) meeting in America's Center in St. Louis, Mo., the Jordan-Eisner comparison will surface amid all of Eisner's incredible accomplishments, including his National Medal of Science award in 1994 from President Bill Clinton for his "seminal contributions in the fields of insect behavior and chemical ecology, and for his international efforts on biodiversity."
Leal will speak on "Tom Eisner--An Incorrigible Entomophile and Innovator Par Excellence" at the Founders' Breakfast meeting that begins at 7:30 a.m., Tuesday, Nov. 19. His presentation, at 8:15, promises to be inspirational, educational and entertaining. (And it's free to all ESA meeting registrants.)
ESA established the Founders' Memorial Award in 1958 to honor the memory of scientists providing outstanding contributions to entomology.
Eisner is known as an exemplary scientist, teacher and leader whose research discoveries focused on how insects use their chemical substances as friends or foes: to attract mates or to defend from foes. He discovered how "a bombardier beetle creates a chemical reaction within its body and then ejects a boiling hot chemical from its abdomen." As Joe Rominiecki, ESA communications manager, said: “Notable among them was deciphering how the bombardier beetle defends itself with an internal exothermic chemical reaction, explosively sprayed at attackers. That discovery topped a lengthy list of revelations about the complex and often surprising biochemicals insects produce, from the bitter, predator-deterring taste of the cochineal scale's brilliant red pigment to the sticky foot secretions that allow the palmetto beetle to cling so tightly to leaf surfaces.“
Leal, whose career spans three decades (see Bug Squad blog) built his career on Eisner's work. So we asked Leal to name 10 interesting facts about Tom Eisner. He obliged.
- Tom Eisner was born in Berlin, grew up in Uruguay, went to college and lived the rest of life in the United States.
- In 1969 Tom gave the Founders' Memorial Lecture to honor Robert Snodgrass. This year he is being honored by the same lecture.
- Tom was an excellent musician; he owned three Steinway Grands, two remains with his daughters and one he gave to the Cornell Music Department
- His application to enter Cornell University was rejected in 1947. Ten years later he was hired as an assistant professor.
- Tom got his BS and PhD from Harvard.
- Tom is considered one of the founding fathers of chemical ecology but mentioned this cannot be proven without a paternity test.
- Tom believed that he did not have good ideas, but he always got good data to support other people's idea.
- One of Tom's many covers of Science appeared on 4th of July (1969) to highlight the “firework” from bombardier beetles.
- For an unknown reason, Tom never traveled by air. He loved to drive long stretches to allow time to connect thoughts and relive experiences.
Leal, whose distinguished career includes co-chair of the 2016 International Congress of Entomology (ICE), serves as a distinguished professor in the UC Davis Department of Molecular and Cellular Biology and is a past chair of the UC Davis Department of Entomology (now the Department of Entomology and Nematology). In his research, Leal investigates the molecular basis of olfaction in insects and insect chemical communication. (See the Leal lab's work on DEET in Entomology Today.)
And another factoid: Leal is the first UC Davis scientist selected to present the Founders' Memorial Lecture. (Medical entomologist Shirley Luckhart of the University of Idaho, formerly of UC Davis, delivered the lecture in 2018.)
One other factoid: Tom Eisner, born in Berlin, was multi-lingual in German, French, Spanish and later English. Leal, born in Brazil, speaks Portuguese, Japanese and English fluently.
(Editor's Note: Listen to Walter Leal's presentation on YouTube)
Today was a Monarch Kind of Day...in Vacaville.
When Art Shapiro, UC Davis distinguished professor of evolution and ecology, searched for butterfly species today at one of his field sites--Gates Canyon in Vacaville--he spotted not one, but two monarchs.
He spotted them separately, both near the bottom of the Brazelton property, and recorded "Two Danaus plexippus: one large, fresh-looking male; one small, unfresh-looking female."
Shapiro, who maintains a research website, Art's Butterfly World (he's monitored the butterfly population in central California since 1972), knows just how scarce monarchs are this year.
Yes, they are. In the fall of 2016, we'd see seven or eight monarchs at a time flutter in for nectar or lay eggs on our milkweed in our Vacaville pollinator garden. This year they're as scarce as the proverbial hen's teeth. However, over the last two weeks, they're starting to appear, one sighting at a time, one monarch a day. They are mostly huge, fresh-looking males seeking nectar from our patch of Mexican sunflowers (Tithonia). A few are females that head over to the tropical milkweed or Tithonia. Solo sightings.
But today was a Monarch Kind of Day.
Around noon, two monarchs arrived at the same time and they both sipped nectar from the Tithonia at the same time. In tandem. Inches away.
It was a Monarch Kind of Day.
The insect, a native of Asia, was first detected in the United States (Palm Beach County, Florida) in 1998, and California (San Diego County) in 2008. HLB, the bacterial disease that it transmits, was first detected in Florida in 2005, and in California (Hacienda Heights, Los Angeles County), 2012.
“The ACP has the potential to establish itself throughout California wherever citrus is grown,” according to the California Department of Food and Agriculture (CDFA).
Now an international team of scientists, led by chemical ecologist Walter Leal of the University of California, Davis, has discovered a new lure or male attractant that's more efficient and effective than the current trap surveillance system of yellow sticky traps.
“Our newly discovered lure captures an average of three times more ACP than the current trapping system, the sticky yellow traps,” said Leal, a distinguished professor in the Department of Molecular and Cell Biology and a former chair of the Department of Entomology and Nematology. “And it works in areas with low population densities. This is particularly important in California, because HLB is already established in urban areas and, therefore, trap surveillance systems are at a premium.”
The research, “Laboratory and Field Evaluation of Acetic Acid-Based Lures for Male Asian Citrus Psyllid, Diaphorina citri, is published today (Sept. 9) in Scientific Reports. It can be accessed free online at https://www.nature.com/articles/s41598-019-49469-3.
The 16-member team, which includes scientists from Brazil and Costa Rica and Benjamin Lehan of California State Polytechnic University, Pomona, wrote in their abstract: “Lures are much needed for improving ACP trapping systems for monitoring populations and surveillance. Previously, we have identified acetic acid as a putative sex pheromone and measured formic acid- and propionic acid-elicited robust electroantennographic responses. We have now thoroughly examined in indoor behavioral assays (4-way olfactometer) and field tests the feasibility of these three semiochemicals as potential lures for trapping ACP. Formic acid, acetic acid, and propionic acid at appropriate doses are male-specific attractants and suitable lures for ACP traps, but they do not act synergistically.”
“An acetic acid-based homemade lure, prepared by impregnating the attractant in a polymer, was active for a day,” they wrote. “A newly developed slow-release formulation had equal performance but lasted longer, thus leading to an important improvement in ACP trap capture at low population densities.”
“The disease has ravaged the citrus industry in China and Brazil,” said Leal, a native of Brazil. “In Brazil, about one-fourth of the citrus trees in the state of São Paulo has been eradicated since 2004 as part of an HLB control strategy. Florida has also sustained severe losses.
Now the disease threatens California's citrus growers “Of note, 1,100 findings of HLB in urban, but not in commercial orchards, suggest that the disease is already established in urban areas in California,” the scientists wrote. “Monitoring ACP populations is essential for integrated vector management and, more importantly, for surveillance. One of the challenges for abatement personnel in areas of low ACP densities is to capture the vector to determine infection status so that control strategies can be implemented before HLB is spread. Therefore, the development of trapping systems is at a premium, particularly the discovery of lures for enhancing ACP captures in areas of low populations.”
Earlier, an international team of scientists led by Leal identified the sex pheromone of the Asian citrus psyllid. Leal, a fellow of the Entomological Society of America and the Entomological Society of Brazil, announced the discovery, encompassing six years of research, at the 10th Annual Brazilian Meeting of Chemical Ecology in Sao Paulo in December 2017. (See Bug Squad blog)
Pheromones and other semiochemicals are widely used in agriculture and medical entomology. “Growers use them as lures in trapping systems for monitoring and surveillance, as well as for strategies for controlling populations, such as mating disruption and attraction-and-kill systems,” Leal noted.
In response to the ACP invasion in California, the CDFA has launched an extensive monitoring program to track the distribution of the insect and disease. They check yellow sticky traps in both residential areas and commercial citrus groves, and also test psyllids and leaf samples for the presence of the pathogen.
Survey methods for ACP include visual inspections; sweep netting, and placement of yellow sticky traps in trees in citrus nurseries, commercial citrus-producing areas and residential properties throughout the state, according to the CDFA. They also place sticky traps in California fruit packing houses, specialty markets, retail stores and airports that receive such produce from areas known to be infested with ACP.
CDFA has set up a hotline at (1-800-491-1899) for residents to report suspicious insects or disease symptoms in their citrus trees.
What are the odds?
Here you are, standing in the garden section of a home improvement store, and you select a tropical milkweed to purchase. You place it on the ground and admire the brilliant yellow blossoms and luxurious green foliage. It's the best of the best. Just as you're about to pick it up and place it in a cart, a monarch lands on it and begins laying eggs.
What are the odds?
That happened to us around Wednesday noon, Sept. 4 in Vacaville as we were purchasing an end-of-the-season Asclepias curassavica.
Most likely, the plant had been in the nursery since last spring, as it was root-bound. We took it home, replanted it in a larger pot, and set it in the sun. Milkweeds like full sun. And monarchs go where their host plant is, whether it be in the wild, in your backyard, in your city park, or in a garden section of your local home improvement store.
Hopefully, the monarch eggs will hatch and this tropical milkweed will yield some caterpillars, chrysalids and adults.
Ironically, we found a monarch laying eggs in the garden section of a home improvement store!
Said entomologist David James of Washington State University, Pullman, who researches migratory monarchs: "That's an amazing story...selecting your milkweed and then having a female come over and deposit a few eggs for you!"
As an aside, as we were purchasing the milkweed, I casually asked the clerk at the check-out line "Have you seen any monarchs here?"
"Not in HERE," she said, surprised I would ask such a question. She tallied up the sale as "Mama Monarch" fluttered around her nursery, unnoticed, laying the next generation.
Curiously enough, a family member recorded a monarch laying eggs in the garden section of that same store the day before. About the same time. Maybe the same monarch. (See YouTube video)
Butterfly guru Art Shapiro, UC Davis distinguished professor of evolution and ecology, who has monitored all butterfly populations in the central valley for more than four decades and publishes his research on a website, says that “this is the biggest milkweed year in northern and central California in living memory. Speciosa is up to 5' tall and some fascicularis almost as big, and both are covered with both genera of Lygaeids (milkweed bugs), plus both oleander and gray aphids. But Monarchs only showed up here about two weeks ago! Lots of milkweed, no Monarchs to use it. I have seen 10 Monarchs in 2019 and have not seen a wild larva since 2017, and I am afield 260 days a year.”
Sometimes life just isn't fair. Entomologist Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at UC Davis, commented “Weirder and weirder. They still haven't found MY milkweed.”