Whether he’s the ‘cockroach guy’ or ‘bed bug guy,’ entomologist Coby Schal is the go-to guy in the battle to control insect pests.
Dr. Coby Schal of N.C. State University’s College of Agriculture and Life Sciences is getting used to being known as “the bed bug guy.”
Schal has made the rounds in local and national media over the past year, from an interview on NPR’s “The People’s Pharmacy” to a talk at the Environmental Protection Agency’s National Bed Bug Summit. His work also is featured in a new National Geographic documentary.
“Nothing surprises me anymore about bed bugs,” Schal says with a chuckle.
He fields requests from all sorts of people, including those in medicine, construction, furniture and textiles.
“We’re working with North Carolina companies quite a lot now, especially furniture makers,” Schal says. “They’re working to prevent their furniture from harboring bed bugs, and they’re interested in our help primarily because we raise bed bugs.
“We probably raise more bed bugs in our lab than anyone in the world, so we’re able to test these companies’ products here in our lab.”
Indeed, it’s difficult to miss the “Bed Bug Containment Area” sign on the door to Schal’s lab. His lab raises 40 different strains of bed bugs that they’ve collected from all over the country, including about 10 strains from North Carolina.
“Different strains have unique features and different genetics, so it gives us a range of different populations to test our strategies on,” Schal says. “We’re working hard to find solutions for bed bug control.”
Before he became renowned for his work on bed bugs, Schal was (and still is) known as “the cockroach guy.” He says that his work with cockroaches continues at full steam, and his lab has made some recent discoveries that could prove to be ground-breaking.
“Almost 20 years ago, my colleague Jules Silverman discovered that there are cockroach populations that refuse to eat certain sugars,” Schal says. “This is fascinating because almost all animals like sugar, especially glucose. The taste of sweet is almost universal in its acceptance.”
Schal thinks Silverman’s discovery means that some cockroaches have evolved to resist insecticide baits that combine glucose with poison.
“By avoiding glucose, they’re avoiding insecticide,” Schal says. “Not much has happened with this discovery over the last 20 years because the mechanism has not been understood.”
Using a combination of behavioral and neurophysiological studies, Ayako Katsumata, a postdoctoral researcher in Schal’s lab, has discovered that these cockroaches have a genetic mutation that makes glucose taste bitter, so they avoid it.
“This opens up a whole new area of molecular biology for us, and I believe it may turn out to be a textbook example of understanding the molecular mechanisms of behavioral resistance,” Schal says.
The discovery is new because most well-known cases of insecticide resistance are purely physiological: a change in the insect’s metabolism renders poisons ineffective. But with behavioral resistance, insects evolve new habits to avoid insecticides entirely. Now Schal’s lab has found sensory underpinnings of one of these behavioral changes.
He describes his work with cockroaches as an “arms race” and says, “We keep hitting them with different insecticides and other control strategies, and they continue to evolve ways to evade them.”
Schal lights up when he talks about bed bugs and cockroaches. He’s fascinated, not grossed out, as evidenced by the wall behind his desk that is plastered with photos of different roaches.
But it hasn’t always been that way.
“I think I’m different from many entomologists, because I don’t remember playing with insects as a kid,” Schal says.
Born in Poland, he moved with his family to Israel at the age of 2. His parents, who were Holocaust survivors, moved the family to the United States when Schal was 15, seeking better education for him and his older sister. The family settled in New York City, and many years later, Schal has discovered that he grew up mere miles from a number of his fellow N.C. State colleagues.
After graduating from high school – the first in his family to do so – Schal enrolled at the State University of New York in Albany. On track for medical school, he decided to change careers when he fainted at the sight of a spinal tap as a volunteer at an Albany hospital.
“I took it as a sign from above that this is not what I should be doing,” he says with a broad smile.
He became interested in zoology and ecology and took a number of graduate-level courses as an undergraduate.
Bypassing a master’s degree, Schal enrolled in a Ph.D. program in entomology at the University of Kansas, during which he spent more than three years immersed in the rainforests of Costa Rica.
“That’s what really got me hooked not only on cockroaches, but also on natural history and behavior and ecology,” Schal says.
To really understand “what makes tropical cockroaches tick,” Schal even became nocturnal and slept during the day, like the creatures he studied.
Describing the cockroaches as “incredible” and “amazing,” Schal discovered and named several new species in the rainforest and also became interested in chemical ecology.
“These cockroaches live in a huge, dark jungle,” he says. “I wanted to know how they find each other, how these insects use chemicals to mediate interactions between the sexes.
“That experience was my real falling in love with insects,” Schal says. “It also set the stage for me wanting to combine lab work with field work throughout my career, and also not to be constrained by disciplinary boundaries.”
Schal doesn’t consider himself an ecologist, a behaviorist, a molecular biologist or the like. He prefers the term “integrative biologist,” one who integrates different areas of biology to solve problems.
After earning his Ph.D. in 1983, Schal accepted a post-doctoral position in chemical ecology at the University of Massachusetts at Amherst.
“I was really comfortable with ecology, but had very little experience with chemistry and combining chemistry with the behavior,” Schal says. Specifically, he wanted to learn the procedure of fractionation, by which a scientist whittles down a collection of chemicals to a single chemical, such as a pheromone, that is responsible for a particular behavior in the opposite sex.
“Once the chemical is identified, then we try to synthesize it,” Schal says. “And if the male responds to the synthetic chemical, we’ve successfully closed the loop, and that chemical can be used for pest control.”
For example, a chemical that attracts the opposite sex can be used to draw pests into traps either to detect a new infestation or to monitor the number of pests in an apartment, restaurant, school or business.
After a year and a half studying the chemical ecology of moths, Schal accepted a position at Rutgers University in 1984 as assistant professor and extension specialist in urban entomology, the study of pests that infest human structures. Although he had never heard of urban entomology, he embraced the new opportunity.
“New Jersey was absolutely the perfect place to be for urban entomology,” he says. “It has the highest density of people in the country, with proximity to New York City and Philadelphia, and a lot of low-income housing that basically became my field sites.”
Ten years later, by then a known expert in urban entomology, Schal accepted the first Blanton J. Whitmire Distinguished Professorship in the CALS Entomology Department at N.C. State.
“I was thrilled,” Schal says. “N.C. State has one of the best entomology departments in the country, and I had tremendous respect for the faculty here. Plus, the opportunity to grow the urban entomology program was very appealing.”
Other schools have tried to lure him away over the years, but Schal says he has no intention of leaving.
“The College’s forward-thinking integration of agriculture and life sciences is unique, and it really suits my style of work,” Schal says. “I’m in a building that houses plant people, geneticists, microbiologists, plant pathologists … the biology and chemistry departments are a stone’s throw away, and poultry science is right next door.
“This is precisely the type of environment that fosters the collaborative style of work I enjoy,” he says.
Schal cultivates that same interdisciplinary approach in his classes, which include a graduate-level course in insect behavior and seminars in chemical ecology and urban entomology. His lab buzzes with three busy graduate students, six postdoctoral fellows and a research specialist.
The value of Schal’s work is also recognized well beyond N.C. State. He is a fellow of both the American Association for the Advancement of Science (AAAS) and the Entomological Society of America, and this summer Schal received the silver medal from the International Society of Chemical Ecology for his career accomplishments.
As for bed bug mania, Schal says it’s a long way from dying down.
“Bed bugs have experienced a resurgence, not only in the United States but globally, for at least 10 years or longer,” Schal says. “Only recently has the problem become so severe that the media have caught up to it.”
Schal explains: A decade ago, bed bugs were a nuisance mostly for the traveling community and hospitality industry. And when travelers picked up bed bugs in hotels and brought them home, they typically had the means to take care of the problem.
But now, because bed bugs have established themselves so well in residential communities, they’ve started moving into low-income houses, shelters and theaters — pretty much wherever humans are. And many of these communities simply can’t afford to control the bed bugs.
“I don’t see the problem subsiding anytime soon,” Schal says. “The magnitude and frequency of bed bugs’ resistance to insecticides is huge, no new insecticides are due to hit the marketplace soon, and no cost-effective strategies for bed bug control have been developed. So we really don’t have a good way to control bed bugs right now, especially in low-income situations.”
His goal? Develop the strategies. Find solutions.
For example, Alvaro Romero, a National Science Foundation postdoctoral fellow in Schal’s lab, is exploring what physical and chemical cues humans emit that excite hungry bed bugs. These cues—heat, carbon dioxide and a host of human body odors—can be used to lure bed bugs to traps and insecticides.
“The key for us in the next five years is to develop better tools for bed bug control,” Schal says. “We’re committed to helping solve this problem.”
And the university backs them in that commitment. It was announced in July that, for his development of a new bed bug baiting system, Schal is among the N. C. State University researchers who are the first recipients of N.C. State’s Chancellor’s Innovation Fund awards. The awardees’ projects will receive seed money that will be used to make the technology more marketable, such as by gathering additional data, conducting market research and building prototypes.