Posts Tagged: Jay Rosenheim
Male praying mantids looking for "a little love" don't always fare well. Sometimes they lose their head. Female mantids can--and do--cannibalize them before, during or after copulation.
Now mantid researcher Katherine Barry of Macquarie University, Sydney, Australia, says that some hungry female mantids are deceptive liars. They emit chemical cues, or pheromones, as if seeking a mate, but what they want is not a mate, but a meal. Her research, "Sexual Deception in a Cannibalistic Mating System? Testing the Femme Fatale Hypothesis," appears in the Dec. 17 edition of the Proceedings of the Royal Society B.
The starving females in her study produced the same chemical cues that the well-fed females did. The deception clearly worked. “The consumption of one male improves body condition by approximately 33 percent and fecundity by approximately 40 percent," Barry pointed out.
In her abstract, Barry wrote: "The Femme Fatale hypothesis suggests that female mantids may be selected to exploit conspecific males as prey if they benefit nutritionally from cannibalism. Such a benefit exists in the false garden mantid Pseudomantis albofimbriata—females use the resources gained from male consumption to significantly increase their body condition and reproductive output. This study aimed to examine the potential for chemical deception among the subset of females most likely to benefit from cannibalism (poorly fed females). Females were placed into one of four feeding treatments (‘Very Poor', ‘Poor', ‘Medium' and ‘Good'), and males were given the opportunity to choose between visually obscured females in each of the treatments. Female body condition and fecundity varied linearly with food quantity; however, female attractiveness did not. That is, Very Poor females attracted significantly more males than any of the other female treatments, even though these females were in significantly poorer condition, less fecund (in this study) and more likely to cannibalise (in a previous study). In addition, there was a positive correlation between fecundity and attractiveness if Very Poor females were removed from the analysis, suggesting an inherently honest signalling system with a subset of dishonest individuals. This is the first empirical study to provide evidence of sexual deception via chemical cues, and the first to provide support for the Femme Fatale hypothesis."
We've seen scores of praying mantids lurking, snagging prey, and devouring their prey, but we've never seen any engaging in sexual cannibalism, which occurs when a female cannibilizes the male before, during or after copulation.
Professor Jay Rosenheim of the Department of Entomology and Nematology, University of California, Davis, has.
In fact, he captured an amazing photo of it and posted it on his website. His daughter, Leah, found the pair in their garden. "Note that the larger female has consumed the head of the smaller male (an example of the famous sexual cannibalism that can occur in this species," Rosenheim wrote. "Amazingly, the decapitated male continued to cling to the female and even attempt to re-initiate copulation several times."
With his permission, we're posting his photo below. We're adding two photos typically seen: a praying mantis waiting for prey--or a mate?--in a bed of cosmos, and another of a gravid praying mantis climbing a bamboo stake.
We don't know if a male lost its head during the male-female encounter, but we do know that we have an ootheca or egg case on our back porch.
Thank you, Mrs. Mantis!
This photo by Professor Jay Rosenheim of UC Davis shows sexual cannibalism. The female (larger one) has just chomped off the head of the male, during sexual reproduction.
A praying mantis perched on a cosmos waiting for prey--or maybe a mate? (Photo by Kathy Keatley Garvey)
Gravid praying mantis. (Photo by Kathy Keatley Garvey)
As its name implies, it's native to Asia. It was first detected in North America in Wisconsin in July 2000. Technically, it’s Aphis glycines Matsumura. In lay language, that's spelled "p-e-s-t."
Now found throughout much of the Midwest, it sucks.
With its mouthparts.
Enter George Heimpel, professor of entomology at the University of Minnesota's Department of Entomology. Heimpel, who received his doctorate in entomology in 1995 from UC Davis, will return to the UC Davis campus Wednesday, Dec. 4 to speak on “Specificity and the Process of Biological Control Using Aphid Parasitoids."
His seminar takes place from 4:10 to 5 p.m. in 122 Briggs Hall. It is scheduled to be recorded for later posting on UCTV. (Editor's Note: The seminar was initially scheduled for noon, but due to midwest storms, Heimpel's flight was delayed.)
"Over the past 25 years or so, importation ('classical') biological control of arthropod pests has undergone a paradigm shift in which emphasis has shifted from an exclusive focus on efficacy to a focus on the actual and potential risks of biological control introductions," Heimpel says. "Host specificity testing is the cornerstone of risk assessment in this new paradigm, and only highly specialized agents are currently approved for release. Here, I describe the process of importation biological control of an invasive agricultural pest in the North-Central U.S.--the Asian soybean aphid."
"Numerous parasitoid species were imported from Asia as potential biological control agents and I focus on five species for which host-specificity testing was done," he says. "Each of these three species tells a different story in terms of host-specificity, the potential for biological control efficacy, and actual success of field releases. Together, these case studies illustrate some potential relationships between safety and efficacy in biological control, and the importance of various traits in mediating safety and efficacy of biological control agents."
Born in Germany, Heimpel grew up mainly in California. He received his bachelor’s degree in conservation and resource studies in 1988 from UC Berkeley and his master's degree in 1991 in entomology and applied ecology from the University of Delaware before heading over to Jay Rosenheim's lab at UC Davis to receive his doctorate in 1995. Heimpel then spent two years as a USDA post-doctoral fellow at the University of Wisconsin in Mike Strand’s lab.
Heimpel now teaches biological control and insect behavior.
And one of his targets is the Asian soybean aphid.
Asian soybean aphid. (Courtesy Wikipedia, Claudio Gratton, University of Wisconsin)
It's exciting to see a promising career unfold.
We first met UC Davis graduate student Alex Van Dam in 2010 when he received a $12,000 award from the University of California Institute for Mexico and the United States (UC MEXUS), an academic research institute dedicated to encouraging, securing, and contributing to binational and Latino research and collaborative academic programs and exchanges.
Then later in 2010 he received a Robert and Peggy van den Bosch Memorial Scholarship for his research on a scale insect. His project: "Investigating Host-Associated Lineage Splitting Within Dactylopius Using Molecular Phylogenetics."
Now Van Dam has just been selected for a National Science Foundation (NSF) Postdoctoral Fellowship to work on insect/host plant research.
The postdoctoral fellowship award is supported by both the Directorate for Biological Sciences and the Office of International Science and Engineering at NSF. During his two-year fellowship, he will work on a project, “New Insights into Insect Host-Plant Generalization: Population Transcriptome Sequencing of Porphyrophora spp.,” under the sponsorship of Uffe H. Mortensen at the Department of Systems Biology, Technical University of Denmark.
Van Dam will identify genes responsible for host-plant range in scale insects, and how they are maintained across populations. “This will be accomplished by testing hypotheses delineating physiological genes responsible for insect host-plant generalization,” he said. “Host-plant generalization is the ability to feed on many different species of plants. I will test if increased dispersal of host-plant detoxification genes in generalists leads to maintenance of functional gene paralogs, that is, gene duplications, across large effective populations.
A native of Los Angeles, Van Dam received his bachelor's degree and master's degree in entomology at UC Riverside and is currently a doctoral candidate and a member of the Entomology Graduate Group. He studies with major professor Bernie May in the Department of Animal Science. Professors Jay Rosenheim and Steve Nadler of the Department of Entomology are members of his dissertation committee.
Meanwhile, Van Dam is gearing up for his exit seminar at the Animal Science Spring Seminar Series. He'll present his seminar on Monday, April 29 from 12:10 to 1 p.m. in Weir Room 2154, Meyer Hall.
Another great success story!
Alex Van Dam, photographed next to a giant cactus.
Want to develop skills that will make your application to graduate school, medical school or veterinary school really stand out from the crowd?
The UC Davis Research Scholars Program in Insect Biology is recruiting undergraduate students who are eager to experience one-on-one research training and mentorship.
This will be the third cohort of students.
The program, now officially approved by the Academic Senate, is coordinated by professor Jay Rosenheim and assistant professors Louie Yang and Joanna Chiu, all of the UC Davis Department of Entomology.
The Research Scholars Program in Insect Biology provides the opportunity to learn research skills in all areas of biology, including:
- behavior and ecology
- population biology
- mathematical bology
- human health
- cell biology
- molecular biology
Applications are now being accepted from first and second-year students and first-year transfer students. The application deadline is April 10, 2013. More information on the program and how to apply is on the program’s website.
Successful venture? Yes, indeed. Two members of the Research Scholars Program in Insect Biology recently received President's Undergraduate Fellowship Program (PUF) grants.
They are Sarah Staley, mentored by medical entomologist Anthony “Anton” Cornel, associate entomologist with the UC Davis Department of Entomology and based at the Kearney Agricultural Research and Extension Center, Parlier; and Don Hoang, mentored by evolutionary geneticist Artyom Kopp, professor in the Department of Evolution and Ecology.
Staley and Hoang were among 25 undergraduate students receiving grants from a pool of 62 applicants. Staley submitted her proposal titled “Prevalence of Leucocytozoa Infections in Potential Vector Populations of Black Flies in Alaska.” Hoang's proposal: "The Yeast/Drosophila Relationship: Is it Meant to Last?”
Read their story on the UC Davis Department of Entomology website.
No small feat. Great things are happening in the Research Scholars Program in Insect Biology. Jay Rosenheim, Louie Yang and Joanna Chiu are making it happen.
Jay Rosenheim, professor of entomology at UC Davis, doing research in a meadow. (Photo by Kathy Keatley Garvey)
It's not just future entomologists who study insects. So do future physicians, veterinarians, chemists, ecologists and scores of others.
Indeed, insects are involved in many biological fields, including genetics and molecular biology; biochemistry and physiology; cell biology; population biology; behavior and ecology; biodiversity and evolutionary ecology; and agroecology.
At UC Davis, a trio from the Department of Entomology faculty wants to make a difference in college students' education. They've formed a campuswide Undergraduate Honors Research Program in Insect Biology to help undergraduates obtain long-term mentoring and research experiences.
Veteran professor Jay Rosenheim and newer faculty members Louie Yang and Joanna Chiu said they want 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. This will be useful for students whose career goals will take them to medical school, veterinary school, or graduate programs in any biological sub-discipline.”
UC Davis freshmen and sophomores interested in applying for the program must do so by May 15 by sending an email to Elvira Hack (email@example.com). In a one-page letter, they will explain their motivation to join the program, and their special interests. Selected students will then be interviewed.
The gist of the program:
- During an initial academic retreat (at the Sagehen Creek Field Station in the Sierra Nevada mountains), faculty will instruct students about the process of science, approaches to choosing research questions, and the core elements of experimental design.
- Students will be placed in a faculty mentor’s laboratory. The goal: to find a strong match between the student’s research interests and the research focus of the mentoring faculty member’s lab.
- Students will be encouraged to take supporting coursework in insect biology (that is, general entomology, insect physiology, insect ecology) to provide the most relevant foundational information for conducting research in insect biology.
- For many participating students, it’s expected that there will be a natural transition from paid positions (when the students are contributing to a larger research effort) to course credits (when the students are pursuing their own independent research).
- Students will receive ongoing training and career guidance in conducting research, scientific writing, presentation of research results at professional scientific meetings, and all aspects of preparing applications for graduate or professional schools.
We applaud the work that Rosenheim, Yang and Chiu are doing, and the 30-some members of the mentoring faculty.
Rosenheim, who joined the UC Davis Department of Entomology faculty in 1990, has long supported the academic and research needs of students. In fact, on May 11, he will receive a UC Davis Distinguished Teaching Award for Undergraduate Teaching. Faculty and students consider him "an extraordinary educator, a remarkable scholar and a superb teacher and mentor."
The ultimate compliment, however, came from an unsolicited comment on the web: “the best teacher at (UC) Davis. Hands down. Take him if you can.”
Lygus bug (Lygus herperus) could be one of the insects studied in the honors program. (Photo by Kathy Keatley Garvey)