Giant water bugs and dragonflies are some of the aquatic insects to be featured at the Bohart Museum of Entomology’s open house from 1 to 4 p.m., Sunday, March 24 in Room 1124 Academic Surge, Crocker Lane, UC Davis campus. The event is free and open to the public.
The toe biters, know as giant water bugs, are in the Belostomatidae family of insects in the order Hemiptera. The largest insects in the order, they are found in freshwater streams and ponds throughout much of the world. In some Asian countries, the giant water bugs are considered a delicacy.
The toe biters or Belostomatids are unique in that the female lays her eggs on the back or wings of a male, who carries the eggs until they hatch.
The flame skimmers, also known as red or firecracker dragonflies, belong to the family Libellulidae and are native to western North America. The Libellula saturata is a common dragonfly in California. They inhabit warm ponds and streams. The immature flame skimmers or nymphs feed on such aquatic insects as mosquito larvae, aquatic fly larvae, mayfly larvae, freshwater shrimp, small fish, and tadpoles. The adults feed on soft-bodied insects including moths, flies, ants and bees.
In keeping with the aquatic insect theme, fly fishing drawers will also be featured at the aquatic insect-themed open house, said Tabatha Yang, Bohart Museum education and outreach coordinator. The drawers hold such specimens as caddisflies, mayflies and stoneflies.
The Bohart Museum, directed by Lynn Kimsey, professor of entomology at UC Davis, houses a global collection of nearly eight million insect specimens and is the seventh largest insect collection in North America. It is also the home of the California Insect Survey, a storehouse of the insect biodiversity. Noted entomologist Richard M. Bohart (1913-2007) founded the museum in 1946.
Visitors can also hold such live specimens as Madagascar hissing cockroaches and walking sticks. The gift shop includes t-shirts, jewelry, insect nets, posters and books, including the newly published children’s book, “The Story of the Dogface Butterfly,” written by UC Davis doctoral candidate Fran Keller and illustrated (watercolor and ink) by Laine Bauer, a 2012 graduate of UC Davis. The 35-page book, geared toward kindergarteners through sixth graders, also includes photos by naturalist Greg Kareofelas of Davis, a volunteer at the Bohart.
The book tells the untold story of the California dogface butterfly (Zerene eurydice), Keller said. Bauer’s illustrations depict the life cycle of this butterfly and the children who helped designate it as the California state insect.
The net proceeds from the sale of this book go directly to the education, outreach and research programs of the Bohart Museum. The book can also be ordered online at http://www.bohartmuseum.com/the-story-of-the-dogface-butterfly.html.
Bohart officials schedule weekend open houses throughout the academic year so that families and others who cannot attend on the weekdays can do so on the weekends. The Bohart’s regular hours are from 9 a.m. to noon and from 1 to 5 p.m., Monday through Thursday. The insect museum is closed to the public on Fridays and on major holidays. Admission is free.
The remainder of the open houses for the academic year:
Saturday, April 20: 10 a.m. to 3 p.m.
Theme: UC Davis Picnic Day
Saturday, May 11, 1 to 4 p.m.
Theme: "Moth-er's Day"
Sunday, June 9, 1 to 4 p.m.
Theme: "How to Find Insects"
For further information, contact Yang at tabyang@ucdavis.edu or (530) 752-0493.
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
March 1, 2013
His seminar, hosted by professor Rick Karban, is from 12:10 to 1 p.m. in Room 1022 of Life Sciences Addition.
Rasmann served as a research associate in the Department of Ecology and Evolution, University of Lausanne, Switzerland, from 2011 to 2013.
Rasmann will be joining the UC Irvine faculty this July. He completed his undergraduate work in Ecology and Systematics, University of Neuchâtel, Switzerland, in 2001. He received his diploma (master equivalent) in chemical ecology from the University of Neuchâtel in 2002. He worked as a postdoctoral research associate in the Anurag Agrawal lab at Cornell University, Ithaca, N.Y., from 2007 to 2011.
Rasmann has delivered 28 seminars worldwide, including in Europe, United States, Canada, South America and Japan. He is the guest co-editor for Frontiers in Plant Science with the special topic, "Above-Below Ground Interactions Involving Plants, Microbes and Insects." He served as an adhoc reviewer for 43 journals, including Proceedings of the National Academy of Sciences, Ecology Letters, New Phytologist, American Naturalist and Ecology.
Rasmann has also served as a grant reviewer for the National Science Foundation in both Switzerland and the United States; Research Foundation, Germany; and the Netherlands Organization for Scientific Research, among others. He co-organized a symposium at the 2008 annual meeting of the Ecological Society of America.
Among his publications:
- Pellissier L, Fiedler K, Ndribe C, Dubuis A, Pradervand J-N, Guisan A, Rasmann S. Shifts in species richness, herbivore specialisation and plant resistance along elevation gradients. Ecology and Evolution. doi: 10.1002/ece3.296.
- Rasmann S, De Vos M, Casteel C, Tian D, Sun JY, Agrawal A A, Felton G W, and Jander G. Herbivory in the previous generation primes plants for enhanced insect resistance. Plant Physiology. 158: 854-863.
- Rasmann S and Agrawal AA . Evolution of specialization: a phylogenetic study of host range in the red milkweed beetle (Tetraopes tetraophthalmus). The American Naturalist. 177: 728-737.
- Rasmann S and Agrawal AA. Latitudinal patterns in plant defense: evolution of cardenolides, their toxicity, and induction following herbivory. Ecology Letters. 14: 476-483.
- Rasmann S, Kollner TG, Degenhardt J, Hiltpold I, Toepfer S, Kuhlmann U, Gershenzon J, and Turlings TCJ. Recruitment of entomopathogenic nematodes by insect-damaged maize roots. Nature 434: 732-737.
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
March 6, 2013
Whitfield will be introduced by her former major professor, entomologist Diane Ullman, associate dean for undergraduate academic programs in the College of Agricultural and Environmental Sciences and a professor and former chair of the UC Davis Department of Entomology.
Whitfield received her master's degree in plant pathology from Ullman in 1999 and her doctorate in plant pathology from the University of Wisconsin, Madison, in 2004.
"Arthropod vectors play an essential role in dissemination of viruses that cause diseases in humans, animals, and plants," Whitfield says. "More than 70 percent of viruses infecting plants and 40 percent of viruses infecting mammals are transmitted from one host to another by arthropod vectors. My research is devoted to investigating plant-virus-vector interactions at the molecular level with the goal of developing a better understanding of the complex sequence of events leading to virus acquisition and transmission by vectors."
"Tomato spotted wilt virus (TSWV) is considered one of the ten most devastating plant viruses and is one of the viruses that we are working with to define the viral and vector determinants of transmission. The virus is transmitted by thrips (Thysanoptera: Thripidae), primarily Frankliniella occidentalis. The TSWV glycoproteins, designated GN and GC, are required for infection of thrips. We found that recombinant GN (GN-S) bound larval thrips midguts in a specific manner and inhibited TSWV acquisition and transmission (Whitfield et al., 2004, and Whitfield et al., 2008)."
"Our findings," Whitfield said, "provide evidence that GN serves as a viral ligand that mediates attachment of TSWV to receptors displayed on the epithelial cells of the thrips midgut. We generated transgenic tomato plants expressing a soluble form of GN with a GFP tag (GN-S::GFP) and found that thrips that fed on these transgenics had significantly lower virus titers and adult transmission efficiencies than thrips fed on TSWV-infected non-transgenic tomato plants. These results demonstrate that an initial reduction in virus infection of the larval insect midgut can result in a significant decrease in virus titer and transmission over the life-span of the vector. Despite the world-wide importance of thrips in agriculture, there is little knowledge of the F. occidentalis genome or gene functions at this time. We developed the first transcriptome analysis of F. occidentalis, and the partial thrips transcriptome was used to characterize the thrips proteome and response to virus infection (Rotenberg and Whitfield, 2010, Badillo-Vargas et al., 2012). Knowledge of thrips recognition and response to virus infection will enable us to develop new strategies to disrupt virus transmission."
Whitfield is the author of numerous publications and book chapters. She has published her work in the Journal of Virological Methods, Insect Molecular Biology, Journal of Virology and the Journal of Economic Entomology, among others.
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
March 8, 2013
In his 224-page book, Page sheds light on how 40,000 bees, "working in the dark, seemingly by instinct alone, could organize themselves to construct something as perfect a a honey comb."
Page, now vice provost and dean of the Arizona State University's College of Liberal Arts and Sciences and Foundation Professor of Life Sciences, marvels at how bees can accomplish these incredible tasks. In synthesizing the findings of decades of experiments, he presents "a comprehensive picture of the genetic and physiological mechanisms underlying the division of labor in honey bee colonies and explains how bees' complex social behavior has evolved over millions of years," according to the Harvard University flier.
Page still keeps his specialized stock of honey bees at the Harry H. Laidlaw Jr. Honey Bee Research Facility at UC Davis. Bee breeder-geneticist Michael “Kim” Fondrk, who worked with Page at Ohio State University, UC Davis and ASU, manages the stock.
In his book, Page talks about the coordinated activity of the bees and how worker bees respond to stimuli in their environment. The actions they take in turn alter the environment, Page says, and "so change the stimuli for their nestmates. For example, a bee detecting ample stores of pollen in the hive is inhibited from foraging for more, whereas detecting the presence of hungry young larvae will stimulate pollen gathering."
Division of labor, Page says, is an inevitable product of group living because "individual bees vary genetically and physiologically in their sensitivities to stimuli and have different probabilities of encountering and responding to them."
Page, who received his doctorate in entomology at UC Davis in 1980, served as an assistant professor at Ohio State University before joining the UC Davis Department of Entomology in 1989. He chaired the department for five years, from 1999 to 2004.
In 2004--the year Page retired from UC Davis--ASU recruited him as the founding director and dean of the School of Life Sciences. At the time, his duties included organizing three departments—biology, microbiology and botany, totaling more than 600 faculty, graduate students, postdoctoral fellows and staff--into one unified school.
As its founding director, Page established the school as a platform for discovery in the biomedical, genomic and evolutionary and environmental sciences. He also established ASU’s Honey Bee Research Facility.
Page is a highly cited author on such topics as Africanized bees, genetics and evolution of social organization, sex determination, and division of labor in insect societies.
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894
March 8, 2013
The research, published March 8 in the PLOS ONE journal, shows that that “temperature effects on larval development time, larval survival and adult reproduction depend on the combination of mean temperature and magnitude of fluctuations,” said lead author Lauren Carrington, a former postdoctoral fellow in the Scott lab and CVEC.
The scientists investigated how realistic fluctuations in temperature during the day influence the life-history traits and population dynamics of the dengue mosquito, Aedes aegypti.
The research, “Effects of Fluctuating Daily Temperatures at Critical Thermal Extremes on Aedes aegypti Life-History Traits,” is expected to lead to greater accuracy of applications for mosquito surveillance and disease prevention.
“An improved understanding of mosquito responses to natural temperature variation,” Carrington said, “will enhance the effectiveness of vector control strategies, thereby reducing transmission of mosquito-borne diseases, such as dengue fever.” By using constant temperatures, scientists can under- or -over estimate values, she said.
“In the field, mosquitoes, and other insects, are exposed to a constantly changing environment, with fluctuations in temperature throughout the day, every day. In the lab, however, experimental protocols generally try to minimize as much variability as possible, and temperature is often the first element to be standardized.”
“After assessing a number of life-history traits at constant temperatures ranging from 12ºC-40ºC to identify the thermal limits of this population of mosquitoes from Thailand, we then reexamined the same traits under cyclic temperatures around a low (16ºC), intermediate (26ºC) and high (35ºC) mean temperature and compared these to appropriate constant temperature controls,” Carrington said.
“The results of our study are extremely important because they provide a better understanding of the life history traits and ecology of the vector, Aedes aegypti, said co-author Veronica Armijos, a Ph.D student with CVEC who studies with major professor William Reisen and works part-time in the Scott lab. “Information like this can be used to help improve current vector control and surveillance strategies."
Research team member Christopher Barker, an assistant adjunct professor with CVEC, part of the UC Davis School of Veterinary Medicine’s Department of Pathology, Microbiology, and Immunology, generated “a stage-structured population dynamic model using our empirical data,” Carrington said. “The model predicted that growth rates could be over- or under-estimated relative to constant temperatures, dependent upon the mean and magnitude of the fluctuations.”
“This is an important addition to a growing body of evidence showing that average temperatures are inadequate to explain variation in mosquito development and reproduction in natural systems,” Barker said. “This study demonstrated additional effects of an often-ignored second dimension-- daily cycling between nighttime lows and daytime highs--particularly when average temperatures were near the limits for mosquito survival.”
“These findings are important in the context of climate change because globally, nights have warmed faster than days, and the changes have been quite pronounced in the ‘urban heat islands’ preferred by Aedes aegypti,” Barker said. “As a result, overall warming trends have been accompanied by reduced daily temperature ranges, and understanding the roles of both will be important for predicting future impacts on mosquito populations.”
Said Carrington: “Our results have epidemiological significance for dengue transmission dynamics, and more generally, highlight that it is not always appropriate to extrapolate the results from laboratory-based experiments directly into the field. Sometimes, allowing for the environmental variation that we as scientists usually try to minimize, is actually important for understanding the ecology of a species in the wild.”
Carrington, Armijos, Barker and Thomas Scott, professor of entomology and director of the Mosquito Research Laboratory, co-authored the paper with Louis Lambrechts, a former Scott lab postdoctoral associate who is now with Insects and Infectious Diseases, Institut Pasteur, France.
Dengue is spread by an infected female Aedes aegypti mosquito, a day-biting, limited flight-range mosquito that prefers human blood to develop its eggs. Dengue is caused by four distinct, but closely related, viruses and the most severe form of disease is life-threatening dengue hemorrhagic fever or DHF.
Some 500,000 people with severe dengue are hospitalized each year, according to the World Health Organization (WHO), and about 2.5 percent of those affected die.
“Dengue takes an enormous toll on human health worldwide, with as many as 4 billion people at risk—half of the world’s population--and 400 million new infections each year,” Scott said.
The National Science Foundation’s Ecology of Infectious Diseases Program funded the project.
--Kathy Keatley Garvey
Communications specialist
UC Davis Department of Entomology
(530) 754-6894