Ecologist Louie Yang, associate professor, UC Davis Department of Entomology and Nematology, has been named the faculty recipient of the 2017 Eleanor and Harry Walker Academic Advising Award from the College of Agricultural and Environmental Sciences (CA&ES).

The award will be presented at the college's Celebration of Advising Reception, set from 4:30 to 6 p.m., Tuesday, May 2 in the Robert Mondavi Institute Sensory Theater, Old Davis Road. Also honored will be student advisor Emma Martinez of the Student Affairs Officer, Animal Science.

The committee was especially impressed with Yang's focus on student diversity, his efforts in helping students link their academic studies to research and other career goals, and his innovative programs working with high school students and connecting these students with undergraduate and graduate student mentors, said Sue Ebeler, the CA&ES associate dean of Undergraduate Academic Programs. 

“His tremendous contributions in advising students seeking to expand their research experience, and programmatic development to enhance such opportunities have helped change the face of undergraduate education in our department,” wrote nominator Steve Nadler, professor and chair of the UC Davis Department of Entomology and Nematology. Nadler described him as a gifted teacher, mentor and scientist who has been instrumental in influencing the lives of many undergraduates.

Yang, who holds a bachelor's degree (ecology and evolution) from Cornell University, 1999, received his doctorate from UC Davis in 2006, and joined the UC Davis faculty in 2009. He is one of the co-founders of the campuswide Research Scholars in Insect Biology (RSPIB)  with professors Jay Rosenheim and Joanna Chiu. The program's goal is to provide academically strong and highly motivated undergraduates with a multi-year research experience that cultivates skills that will prepare them for a career in biological research.

In addition to his RSPIB mentoring, Yang mentors many undergraduates in his lab. He has welcomed and mentored students from UC Davis and from around the country with the National Science Foundation Research Experiences for Undergraduates Program (Natalie Gonzalez and Jacob Penner) and the UC Davis-Howard University Historically Black Colleges and Universities (HBCU) Ecology & Evolution Graduate Admissions Pathways (EEGAP) program (Kabian Ritter).

In the past year, Yang mentored 15 undergrads in his lab. The studies involved:

• The nonconsumptive effects on monarch development to see if parasitoid avoidance behaviors in early development have a long-term cost for monarch development. 
• the factors that contribute to herbivory by generalist herbivores on milkweed.
• the effects of a recently observed plant foliar fungal pathogen on milkweed on monarch growth and development. 
• the costs of switching milkweed species for monarch larvae.
• The density dependence in larval and adult blue milkweed beetles
• the fractionation of H and O isotopes from water to milkweeds to monarchs, using three species of native California milkweeds reared with water from two distinct isotopic sources

Yang also launched the Monitoring Milkweed-Monarch Interactions for Learning and Conservation (MMMILC) Project  in 2013 for high school students in the environmental science program at Davis Senior High School or those associated with the Center for Land-Based Learning's GreenCorps program. They monitor milkweed-monarch interactions in a project funded by the National Science Foundation. Yang and UC Davis undergraduate and graduate students serve as mentors.

“The goal of the MMMILC Project is to better understand the ecology of milkweeds and monarch butterflies,” Yang explains on his website. “We are particularly focused on understanding the role of seasonal timing (phenology) on the interactions between milkweeds and monarchs…While this project is centered around milkweed-monarch interactions, we are really interested in all of the creatures that interact with milkweed. The ecological community of surrounding milkweeds includes lots of fascinating species interactions, and we are interested in understanding how those interactions are connected over time.”

MMMILC accomplishments include weekly measurements on 318 plants for 8 months/year; approximately 89 participants spent 24,000 field minutes; about 30,000 plant and 1100 monarch measurements; and weekly data quality checks and internal cross-validation

Yang strongly supports student diversity, under-represented groups, and graduate education. Two of his undergrads were supported by a supplemental Research Experiences for Undergraduates (REU), including one Latina. He has mentored grad students from the Entomology Grad Group, the Grad Group in Ecology and the Pop Bio Grad Group. He serves on many guidance, exam and advising committees. He also has participated in mentoring workshops at the Center for Population Biology. 

Also noted for his teaching and research, Yang was nominated by the Associated Students of UC Davis in 2012 for an Excellence in Education Award. He received a prestigious National Science Foundation Faculty Early Career Development Award of $600,000 in 2013.

DAVIS--Newly published research on California's overwintering monarch butterflies confirmed many previous migratory studies, but found some unexpected and surprising patterns of movement, said lead researcher Louie Yang, a community ecologist with the UC Davis Department of Entomology and Nematology. 

The research, published in the early online version of the journal Ecography, examined the natal origins of butterflies at four overwintering sites. Each of the four sites showed substantial variations in wing morphological values, indicating local and long-distance, the researchers said. 

Natal origins of butterflies collected from the two northern sites--Lighthouse Field State Beach and Moran Lake, both in Santa Cruz County--varied significantly from those collected at the two southern overwintering sites--Pismo State Beach, San Luis Obispo County; and the Coronado Butterfly Preserve, Santa Barbara County, they said. 

“We hope that this paper improves our understanding of where monarch butterflies grow up in western North America,” said Yang, an associate professor. “This study uses a naturally occurring continental-scale pattern of hydrogen isotopes in precipitation in order to estimate the natal origins of overwintering butterflies. Building a clearer understanding of where they come from could help us better understand many aspects of their ecology.” 

The research is the work of Yang; Dmitry Ostrovsky of the University of Colorado, Denver; and Matthew Rogers and Jeffery Welker of the University of Alaska. 

The research team set out to answer two key questions: “How do broad geographic areas of potential natal habitat contribute to the overwintering population of western monarch butterflies in California?” and “How does the individual variation in the wing morphology of overwintering western monarch butterflies correlate with estimated migratory distance from their natal origins?” 

They first compared the wings of 114 monarch butterflies collected from the four overwintering sites with a continental-scale monarch butterfly wing isoscape derived from the U.S. Network for Isotypes in Precipitation (USNIP) database. They used spatial analyses of stable isotype ratios and correlations with wing morphology. Then they examined the correlations of monarch butterfly forewing size and shape. 

Of the 114 butterflies sampled, they found that 30 percent developed in the southern coastal range; 12 percent in the northern coast and inland range; 16 percent in the central range, and 40 percent developed in the northern inland range.

“Interestingly, the two most northern overwintering sites in the study showed the largest contributions from the southern coastal range (Lighthouse Field, 45 percent; Moran Lake, 37 percent; Pismo Beach, 22 percent; and Coronado Preserve, 24 percent) while the two most southern overwintering sites showed the largest contributions from the northern inland range (Lighthouse Field, 30 percent; Moran Lake, 35 percent; Pismo Beach, 53 percent; and Coronado Reserve, 39 percent),” they wrote.

The researchers randomly collected the monarchs Dec. 4-6, 2009 from aggregations in trees. The collecting resulted in: 19 males and 9 females from Coronado; 22 males and 8 females from Pismo State Beach; 20 males and 10 females from Moran Lake; and 18 males and 8 females from the Lighthouse Field State Beach.

In addition, the male monarch butterflies showed mean total masses that were 5.8 percent larger than those of the females.

The monarch butterfly (Danaus plexippus) of North America overwinters along the California coast and in the central mountains of Mexico. Previous studies have indicated that the western monarchs or those from natal habitats west of the Rocky Mountains, overwinter along the California coast. Those that develop east of the Rockies overwinter in central Mexico.

Their research paper, “Intra-Population Variation in the Natal Origins and Wing Morphology of Overwintering Western Monarch Butterflies (Danaus plexippus), is can be read in early view at http://onlinelibrary.wiley.com/doi/10.1111/ecog.01994/abstract. It will be incorporated into an online issue, perhaps within six months, but it has not yet been assigned to an issue, said journal managing editor Maria Persson.

The project was funded in part by a National Science Foundation (NSF) Early Career Development Program grant awarded to Louie Yang, and a NSF Major Research Instrumentation Program grant awarded to Jeffrey Welker.

Information on map: Isoscape of estimated δDm values for the wings of monarchs originating throughout western North America, based on a weighted average of precipitation δDp values throughout the growing season (see Methods). Isoclines are shown at δDm = –130, –115 and –100‰ to show four broad regions; estimated δDm values become increasingly negative moving inland and northward. Pie charts show the proportion of individual monarchs from (a) Lighthouse Field, (b) Moran Lake, (c) Pismo Beach and (d) Coronado Preserve with δDm values that correspond with the four isoscape regions. Filled points represent precipitation collection sites in the USNIP database; unfilled points represent overwintering sites. (Courtesy of Louie Yang)

DAVIS--Student applications for the Research Scholars Program in Insect Biology, University of California, Davis, are now being accepted through Friday, April 10. 

Eligible to apply are first and second-year students and new transfer students interested in a one-on-one training and mentorship in insect biology.

The program can provide the opportunity to learn research skills in all areas of biology, including behavior and ecology, biodiversity, agroecology, population biology, mathematical biology, human health, cell biology, biochemistry and molecular biology, said co-director and co-founder Jay Rosenheim, professor of entomology, Department of Entomology and Nematology, UC Davis. 

Details are at http://ucanr.org/sites/insectscholars/

Rosenheim and Louie Yang and Joanna Chiu, fellow faculty members of the UC Davis Department of Entomology and Nematology, organized the program in 2011 to provide undergraduates with a closely mentored research experience in biology. The program's goal is to provide academically strong and highly motivated undergraduates with a multi-year research experience that cultivates skills that will prepare them for a career in biological research and useful for students whose career goals will take them to medical school, veterinary school, or graduate programs in any biological sub-discipline. More than 40 mentoring faculty are involved in the program.

One of the many success stories is Jessica West, a member of Joanna Chiu's molecular genetics lab. She recently received the $2500 undergraduate student award in the President's Global Food Initiative Student Fellowship Program, sponsored by the UC Office of the President.

West, majoring in biochemistry and molecular biology, works in the Chiu lab on the Spotted Wing Drosophila (Drosophila suzukii or SWD), a serious pest of fruit crops. In collaboration with scientists in the U.S. and around the world, including Frank Zalom, UC Davis professor of entomology, West is surveying populations of SWD using next-generation sequencing to determine the extent of possible insecticide resistance.

West was one of eight students among a pool of 50 selected to be a member of the Class of 2013, Research Scholars in Insect Biology Program.

Monarch butterflies established just 200 years ago in remote Pacific islands are undergoing contemporary evolution through differences in their wing span and other changes, believes Hugh Dingle of the University of California, Davis, an international authority on animal migration who just received a grant to study the monarchs on three Pacific islands.

Dingle, a UC Davis emeritus professor of entomology and author of two editions of “Migration: The Biology of Life on the Move,” said his previous studies reveal that migrant and resident monarchs exhibit different wing shapes.

Dingle is the recipient of the UC Davis Edward A. Dickson Professorship Award to research “Monarchs in the Pacific: Is Contemporary Evolution Occurring on Isolated Islands?”

Dingle will be working with community ecologist Louie Yang and molecular geneticist Joanna Chiu, assistant professors in the UC Davis Department of Entomology and Nematology, to examine the ecology and physiology of monarch butterflies (Danaus plexippus) in three islands where contemporary evolution might be expected. The islands are Oahu (Hawaii), Guam (Marianas) and Weno (Chuuk or Truk).

“This is the necessary first step in a long-term analysis of the evolutionary ecology and physiology of monarch butterflies on remote Pacific islands,” said Dingle, a fellow of the American Association for the Advancement of Science and the Animal Behavior Society.

Dingle said the monarch, widely distributed “for eons” in the New World, is fairly new to the Pacific islands and to Australia. “In addition to North America, the monarch occurs as a resident throughout the Caribbean and Central and northern South America—and probably as a migrant farther south. One of the more intriguing aspects of its distribution is that beginning in the early part of the 19th century, it spread throughout the Pacific all the way to Australia, where there are now well-established migratory and non-migratory populations.”

Dingle speculates that the monarchs arrived in the Pacific islands with their host plant, milkweed, which was valued at the time for its medicinal properties. Some of the islands are extremely isolated, he said.

An analysis of a monarch population in Hawaii shows that resident monarchs have shorter, broader wings than the long-distance migrants. The Hawaii butterfly wings were shorter than the eastern U.S. long-distance migrants, but “not so short-winged as the residents in the Caribbean or Costa Rica, which have been present in those locations for eons, rather than the 200 years for Hawaii.”

“If there are indeed wing shape changes associated with evolution in isolation, are there other changes that may have occurred under selection and local adaptation for residency?” Dingle wonders. “Are there other changes that may have occurred under selection and local adaptation for residency? Examples of such traits might be changes in flight muscle physiology, changes in photoperiodic diapause response, changes in the characteristics of orientation ability and its relation to antennal circadian rhythms, or changes in the reproductive capacity or tactics (re-colonization of ‘empty' habitats is no longer part of the life cycle).

“Diapause and fat storage, necessary to support migration, are triggered by short photoperiods,” Dingle said, “and the butterflies orient using a sun compass synchronized to a circadian rhythm in the antennae. Overwintering sites in North America include the Transvolcanics Mountains of central Mexico, and the California Coast, particularly Santa Cruz, Pismo Beach, and Pacific Grove.

The UC Davis team will study the monarchs on the three islands and compare them with California mainland monarchs. Using an image analyzer and camera equipment available in Yang lab, the team will photograph “chilled” butterflies in a fixed position with wings spread and then release them back into the wild. The image analyzer will measure different variables, including length, width and angles from the photographs and compute multivariate-shape parameters.

The Chiu lab will assess genetic differences using a transcriptomic approach with monarch caterpillars. “This assessment will be greatly facilitated by the fact that the monarch genome has now been sequenced,” Dingle noted. “A major focus of Dr. Chiu's research is circadian rhythm genes, and these will be especially relevant here because of the association of these genes with monarch capabilities. Because the monarch cell line is cycling and has a functional circadian clock, effects of mutations in specific clock genes can be examined with regard to clock function.”

Dingle expects the one-year research program not only to form the basis for “long-term research on the evolutionary genetics of behavior, ecology and physiology on Pacific island monarch butterflies” but on “the general aspects of island biogeography, a subject of great practical theoretical interest in evolutionary biology.”

Both Yang and Chui currently have grants involving research on monarch butterflies. Yang also studies island ecology.

Dingle, who received his bachelor's degree in zoology from Cornell University and his doctorate in zoology from the University of Michigan, served on the faculty of the UC Davis Department of Entomology (now the UC Davis Department of Entomology and Nematology) from 1982 to 2002 and achieved emeritus status in 2003. He is a past president of the Animal Behavior Society and former secretary of the International Society for Behavioral Ecology.

Dingle published the second edition of “Migration: The Biology of Life on the Move” (Oxford University Press) in November 2014. It is the sequel to the widely acclaimed first edition, published in 1996. National Geographic featured Dingle in its cover story on “Great Migrations”  in November 2010.  LiveScience interviewed him for its November 2010 piece on “Why Do Animals Migrate?”

Dingle was interviewed recently by Italian journalist Giovanna Faggionato for a piece on migration in the Pirelli magazine.