Tufts biology Professor Philip Starks and his graduate student researchers are uncovering the secret lives of honeybees and paper wasps.
There are certain challenges that come with researching honeybees and paper wasps. They may, for instance, become quite agitated if you approach them on the wrong day. Or, if it's a particularly harsh winter, thousands could perish in the blink of an eye and with them would go your research sample. But one of the biggest challenges must be to remain calm when one happens to find its way down your shirt.
"A few years ago, I was working in an enclosure of paper wasps," says Philip Starks, an assistant professor of biology at Tufts. "I wanted the work to be perfect and at some point one of them crawled down the back of my shirt. It started to sting, but all I could think about was taking my shirt off gently so I didn't kill the wasp."
The risk of getting stung comes with the territory for Starks and his team of researchers, who include biology graduate students Noah Wilson-Rich and Susan Weiner, as well as several Tufts undergraduates.
Together, as members of the Starks Laboratory at Tufts, they are researching honeybees and paper wasps—examining everything from how honeybees respond to disease to the competition that can ensue when paper wasps form a colony.
As Starks explains, these insects are ideal research subjects for a number of reasons.
"These are eusocial animals and as such they anchor a particular continuum in social evolution," he says. "They have overlapping generations, cooperative brood care, and a reproductive division of labor. In addition, they have short generation times, so we can actually study something like the lifetime reproductive success of individual paper wasps within one year. We can do a tremendous amount of work in a short period of time."
The work of the lab takes place both at Tufts' Medford/Somerville campus and at the university's Cummings School of Veterinary Medicine, where Starks has an apiary of twenty-five honeybee hives. Since the honeybees are active during the fall, spring and summer, the majority of the fieldwork is done during these times. A typical research day in Grafton, MA, the home of the School of Veterinary Medicine, might involve observing and collecting bees from various hives for analysis back at the Tufts Medford/Somerville campus. The paper wasp work involves gathering nests from field sites at the veterinary school and other locations. The nests are then pinned up in enclosures (i.e., wood and mesh huts) at Tufts for further study.
While in the field, Starks and his graduate students get up close and personal with their research subjects on a regular basis.
"When I'm working with Phil, we go right into the colonies," says Noah Wilson-Rich. "The bees usually aren't too happy, and that's when I'm out with my smoker. I add smoke to the hive and it disrupts their chemical signaling system so they can't really communicate with each other. This was a technique that Phil taught me last summer."
In addition to overseeing the research of his students, Starks is also primarily responsible for the apiary itself.
"Honeybees pretty much take care of themselves, but I'm still involved with them during the year," he says. "I might provide them with some supplemental pollen so they can start rearing their young early or I might give them some sugar water later in the year if they haven't stored enough honey for the winter. I also look to see if any diseases are present in the hives."
WITHIN THE HIVE
What do most people see when they look at a beehive? From a distance, they see nothing more than small specks whipping to and fro in a chaotic pattern. But, as Starks shares, there's much more going on than meets the eye.
"I think everyone should take the opportunity to sit near a honeybee hive and just watch," he says. "It's like a crazy airport with bees coming and going. It's a view you don't normally get."
Starks and his students have gotten this view and then some, and their research has helped expose a truly unique world.
"One of our discoveries has to do with the ability of a colony to mount a group level temperature response to disease," says Starks. "We introduced a particular infection that impacts young, developing larvae into some of our hives and used temperature probes to measure the temperature of the brood comb. We noticed that the temperature within the hive spiked in response to the infection. An infection like this can do a number on a colony, so what honeybees do is elevate the temperature of a hive to the point that the fungal pathogen can't take root in the larvae. It's sort of a preventative fever."
Along with this group response, the Starks Lab has also found that when the temperature outside a hive fluctuates honeybees can form a living "heat shield" and that worker paper wasps, instead of helping their fellow workers, sometimes depart the hive to form their own.
Assistant Professor Philip Starks with graduate students Susan Weiner and Noah Wilson-Rich
The lab also has its share of other questions, some of which are being explored by Noah Wilson-Rich and Susan Weiner. "Many paper wasps found a colony with another reproductive female, which is usually her sister," says Weiner. "When this happens, they form a linear dominance hierarchy where the dominant animal will lay most, and sometimes all, of the eggs. The subordinate basically takes a worker role. However, when the rest of the workers emerge the subordinate female usually disappears. It was believed that either the dominant female or the workers would chase her away. But there isn't an increase in aggression observed. My hypothesis is that, instead, these subordinates go off and try to usurp or adopt other nests in the area and raise workers that are relatively near to emergence. They will then be able to raise their own brood of reproductives."
Noah Wilson-Rich's primary research differs from Weiner's both for his research subjects (i.e., honeybees) and the area he's focusing on (i.e., immune response).
"My major bee study this year has been to compare immune strength between colonies," says Wilson-Rich, who visited the Veterinary School a few days a week last summer to collect bees from different colonies. "One of the questions I'm exploring is if the genetic diversity of a colony corresponds to their immune strength or otherwise health. There has been documentation in the scientific literature of this relationship in honeybees, whereas colonies from polyandrous queens had less variance in survival than colonies with monogamous queens in response to a disease challenge. I'm trying to find out how genetic diversity affects particular aspects of the immune response, and then incorporate these data into a mathematical model of how diseases are spread through social groups. Epidemiological questions are tough to answer empirically with humans, because it's unethical to send an infected person to a crowded area and record how the disease spreads. Honeybees, however, make an excellent model system to study the relationship between group dynamics and disease transmission."
Wilson-Rich plans to write a research paper on this cross-colony immune response in the future. For now, though, most of his work involves analyzing the data he has gathered.
"I am testing the hypothesis that colonies with low genetic diversity will have more variability in their disease susceptibility," says Wilson-Rich, who is also researching the immune strength of the invasive paper wasp species, Polistes dominulus. (continued)
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Profile written by Robert Bochnak, G07, communications specialist for the Office of Graduate Studies.
Photos by Jodi Hilton for Tufts University
This story ran online on June 4, 2007. It originally appeared in the Spring 2007 edition of Tufts Alma Matters, the magazine for graduate alumni of Arts and Sciences and Engineering.