With funding from a 5-year NSF grant, Erica Van Ness ’18 and biology professor Nina Theis, Ph.D., traveled deep into the heart of Trinidad to conduct research on tropical cucumber flowers, scent production, and fly-wasp interactions. Stateside, Jeszy McGuire ’19 helped them begin analyzing their data. Part two of this story appears here.
Fieldwork in Foreign Lands
Student-faculty research happens every day at Elms. In fact, it’s one of the threads that makes the tapestry of our campus community so vibrant. But research projects that take place beyond the comfort of campus, outside the United States, are less of an everyday occurrence.
For Erica Van Ness ’18 and Associate Professor of Biology Nina Theis, Ph.D., their interest in the ecology of scent production sent them on a transnational research trip to the Caribbean. On the island of Trinidad, they harvested the fragrances of tropical cucumber flowers to better understand fly-wasp interactions.
Erica Van Ness ’18 (left) and Associate Professor of Biology Nina Theis, Ph.D.
To date, scientists have been unable to explain the extreme diversity of Blepharoneura, a genus of tropical fruit fly. “Blepharoneura was once thought to contain just 13 species, but biologists have now identified more than 130 species in the wild,” Prof. Theis explained.
While the biodiversity of the flies themselves holds plenty of riddles, scientists are also at a loss when it comes to understanding how wasps — the natural predators of the flies — locate their prey.
The Elms team hypothesized that scent holds the key to this eco-puzzle because the parasitoid wasps always manage to find the flies, even though they feed deep inside the floral tissue of the cucumber flowers, out of sight.
“On top of figuring out how herbivory works, we’re investigating how parasitic animals find their hosts,” Erica said. “There are so many insects that are not classified really well. Our research can help reduce that number.”
While Prof. Theis and Erica gathered their flower samples in Trinidad, the flora actually appear throughout the tropics — including Peru, Ecuador, French Guiana, Costa Rica, Colombia, and Bolivia. This vast stretch of geography positions the team’s research within a global context. By tracing the wasp’s survival patterns — and knowing exactly how they sniff out the right species of fruit fly — the team is deepening our understanding of ecology around the globe.
Stopping to Smell the Flowers
Over the course of two weeks, Prof. Theis and Erica collected 236 samples from three species of flowers: Psiguria triphylla, Psiguria umbrosa, and Gurania spinulosa. Between locating their specimens, bagging the flowers and setting up tubing, trapping the fragrances of the flora, and processing their samples in a field station, they worked around the clock, sweating it out in a tropical paradise.
“The cucumber plants aren’t very fragrant,” Erica said. “Normally it only takes two, maybe four hours to collect scents. We had to let the pumps collect for seven hours here, which is the longest time Prof. Theis has ever had to keep them running.”
Collecting samples from a cucumber flower in Trinidad.
Back on campus, Erica and Jeszy McGuire ’19, a senior biology major, began processing the samples from Trinidad in the Lyons Center. They began by washing the scent off of the scent traps and and then concentrating the “wash”. When the fragrances achieved the proper concentration, the team then injected anisole, an aromatic compound not found in the plants, which can be used to calibrate plant fragrances.
The samples were then brought to the University of Massachusetts Amherst, where they were injected into a GC-MS (gas chromatograph coupled to a mass spectrometrometer). In layman’s terms, the complex floral scent blend — which can have more than 100 different compounds — was first separated into its individual components. Then, each compound was identified.
In fall 2018, a new cohort of biology students will run a series of tests on each sample, trying to uncover patterns in the scent. Their ultimate goal? Discovering whether a specific chemical compound in the flowers’ odor acts as a signal to the wasps, leading them straight to Blepharoneura flies.
A breakdown of the chemical compounds found in a sample.
“After the scent was collected in Trinidad, we dissected the flowers. Our collaborators are in the process of analyzing the DNA from the insects that were found inside the flowers,” Prof. Theis said. “The DNA analysis can detect not just the species of fly that was inside the flower, but also the wasp that was inside the fly.”
“It’s such a multifaceted study,” Jeszy said. “It’s really about how different components of scent affect different behaviors — how they drive different species interactions.”
Erica Van Ness ’18 (left) and Jeszy McGuire ’19 in the Lyons Center for Natural and Health Sciences.
Unlike some disciplines, STEM fields have a reputation for collaboration, especially where research is concerned. When Prof. Theis and Erica traveled to Trinidad, they joined another small research team from Cornell College.
“Our work is supported by a Dimensions of Biodiversity National Science Foundation Grant,” Prof. Theis said. “It’s a very prestigious five-year grant. There are teams from five different institutions working on this project.”
The lead researcher on the NSF grant is Marty Condon, Ph.D., a professor of biology at Cornell College. Prof. Condon invited Prof. Theis to join her in Trinidad due to her expertise in plant signaling and scent.
The two research teams fell into a friendly rhythm at their field station every night, burning the midnight oil as they dissected flowers and flies. Whereas Prof. Condon’s work investigates the flies and wasps themselves, Prof. Theis’ research examines the workings of the scent signals that transpire between predator and prey.
As an active member of International Club at Elms, Erica is no stranger to the value of cross-cultural experiences, research-related or otherwise. Having previously studied abroad at the the University of Stirling in Scotland and visited the University of Kochi in Japan, she said that conducting research internationally benefited her job search after graduation.
“The fieldwork from this internship helps, because I’ve done the intense lab and field research that most students definitely don’t have at this stage,” she said. “Companies are telling me that they value this type of experience.”
Being treated as a colleague on the research project, rather than just a student, also added to her confidence.
“I was super nervous at first,” she said. “Prof. Theis may have been in charge of me, but we had to do it all together. You become coworkers, in a sense.”
“It was interesting experiencing a country that neither one of us had been to before,” she added. “Suddenly we’re in Trinidad saying, ‘That looks like the right direction,’ trying to figure it all out.”
Prof. Theis agrees. “Research experiences for students are invaluable in today’s competitive world,” she said. “Not only do students learn how hard they have to push themselves, they also learn the skill of GC-MS analysis. Having this on a resume really makes our students stand out.”
As she enters her senior year at Elms, Jeszy is looking forward to drawing on her real-life experience to prepare for a career as a science teacher.
“It was beneficial to be able to take techniques we learned in the lab and other courses and actually apply them to a real life research project,” she said. “It gives you an idea about what a research biologist would do day-to-day.”
Now a lab assistant at Avista Pharma Solutions, Erica applies her knowledge of biochemistry to support a variety of research and development projects. Her advice to Elms students interested in science? Take advantage of every opportunity you can.
“Sophomore year, I was able to do independent research,” she said. “Sometimes, at other schools, you can’t get that experience so quickly.”
“Having the chance to spend extra time in the lab and further my education was worth all the while,” she added. “I’m sitting down looking at jobs and thinking, ‘Wow, I actually have years of experience already. I actually understand this, and know how to use this technology and do these techniques.’ ”
While STEM was Erica’s academic passion at Elms, international travel was her cultural one. She urges fellow college students to leave any potential fears about going abroad back in their dorms, and to get out and see the world.
“Don’t be afraid. Use that fear to empower you to do it,” she said. “I’m a completely different person because of travel.”
Experiential learning is a priority at Elms College. Check out our experiential learning funds page to learn more about how you can receive funding for mission trips, study abroad opportunities, research projects, and field work.