Biologists at the University of California, Riverside, have discovered that the complex odor-detecting machinery of the fruit fly Drosophila is heavily influenced by one specific odor receptor. This same receptor also exists in crop-damaging fly species and disease-carrying mosquitoes, opening the possibility for new chemical cocktails to control pests and render people “invisible” to mosquitoes.

Led by Anandasankar Ray, associate professor of molecular, cell and systems biology, the researchers published their findings online Feb. 8, 2018, in the journal Neuron.

Odor receptors are proteins that festoon the antennae and sensory appendages on the heads of fruit flies. Odorant molecules plug into them like a key into a lock, activating the odor- detecting machinery in the fly brain to trigger behaviors, such as homing in on ripe fruit. Deciphering the odor-detecting machinery has been incredibly difficult, Ray said, because the fly has more than 100 different odor receptor proteins, which feed into an even more complex odor-processing circuitry in the brain.

In their studies, Ray and his colleagues zeroed in on one odorant receptor made up of two subunits. This receptor became a target when initial experiments hinted that the largest family of receptors from the odorant receptor family was not governing the flies’ attraction to odorants (called polyamines and amines) in a test chamber. These chemicals emanate from many sources, including ripe fruit, making them important signals for many insects.

Their experiments pinpointed the specific receptor as the culprit, because when the researchers genetically or chemically switched off the receptor pathway, the flies were no longer attracted to polyamines.

“The identification of this receptor was confusing to us at first, because in past studies switching it on caused aversion in flies, rather than attraction,” said Ray. “But to our surprise, our experiments showed that the attraction to polyamines came about because they act as inhibitors of the receptor.”

What’s more, the researchers found, the inhibition was not an on-off effect, but was graded. So, as flies moved toward higher concentrations of a polyamine, the receptor inhibition would be dialed up, luring them toward the highest concentrations, aiding their quest for fruit.

EFFECTS ON MOSQUITOES. The researchers also conducted experiments with mosquitoes, since they possess the same receptor. Their experiments revealed, however, that the receptor in mosquitoes functioned in an opposite way than in the flies, with activation triggering attraction to an odorant.

In their experiments, the researchers tested the effects of a polyamine called spermidine on the mosquitoes’ reaction to human odor — discovering that it masks attraction to the odor. However, they found in further experiments that the spermidine did not mask attraction to a human arm.

“A human arm has a lot more to attract mosquitoes than just skin odor,” said Ray. “One of the strongest attractants is the body temperature. We recognized by our experiments that, while spermidine can make the skin odor by itself less attractive, it is not effective by itself as a masking agent for mosquito behavior toward human targets. Perhaps additional substances that can block the mechanism for sensing human heat or humidity would be needed. Nevertheless, this is a valuable step forward toward such a blend,” he added, noting such a cocktail of natural chemicals could be safer than the widely used repellent DEET.

In the laboratory, Ray and his colleagues are working with the three major disease-carrying mosquito species: Anopheles mosquitoes that can transmit malaria; Aedes aegypti that can transmit yellow fever, dengue and Zika viruses; and Culex that can transmit West Nile virus.

Ray said their findings also have led to a more sophisticated understanding of how the odor-detecting machinery processes signals from the complex mixtures of odorants the fly detects in nature. The researchers found that an odor that inhibited the carbon dioxide receptor but was aversive to the flies became an attractant when they increased levels of carbon dioxide in the environment, which is detected by the specific receptor.

“In the past we thought of odors like the keys on a piano,” explained Ray. “As you press more keys at the same time, you get an additive mix of tones. But we are showing, perhaps for the first time, that a combination of odorants is not necessarily additive. It can end up producing an output that represents a subtraction.” Such basic insights, said Ray, will have application throughout the field of sensory reception, even in human studies.

In further research, Ray and his colleagues will continue to explore the odor-detection machinery in mosquitoes, seeking natural chemicals that could be used in products to render mosquitoes insensitive to humans. They also will extend their studies in the fruit fly Drosophila melanogaster to agricultural pests such as the spotted wing Drosophila, which infests berries and tree fruit such as peaches and grapes.

The title of the Neuron paper is “Signaling Mode of the Broad-Spectrum Conserved CO2 Receptor is One of the Important Determinants of Odor Valence in Drosophila.” Lead author of the paper is Dyan MacWilliam, a postdoctoral fellow in the Ray laboratory. Other co-authors are Joel Kowalewski of the Interdepartmental Neuroscience Program, Arun Kumar and Crystal Pontrello.

By Brad Harbison

What happens when 45 employees quit on the same day? Attendees of this year’s NPMA Academy found out from Kristen Hadeed, who as an undergraduate student at the University of Florida founded Student Maid, a successful cleaning company that employs primarily college students.

Not long after Hadeed started her business she landed a contract to clean 800 student apartments, so she had to scramble to find employees. Hadeed was able to hire 70 students, but she did not provide these workers with much training, and she provided few insights as to what the jobs entailed. The end result was that 45 employees came to her house en masse and quit. One of the 25 workers who did stay suggested Hadeed coax the other workers back with “pizza and a paycheck.” It worked. Moreover, Hadeed rolled up her sleeves and joined cleaning teams. “It helped them see me as a human,” she recalled.

Following this and other experiences, Hadeed realized her business would not succeed unless she did more to create a culture where employees could “learn and grow into leaders.” She then provided attendees with thoughts on what leaders can do to create a winning environment.

Encourage empowerment —  When an employee comes to a leader with a problem, the easy thing for the leader to do is solve it themselves. A better approach, Hadeed said, is to ask that employee to come up with two possible solutions. “If they can solve that problem themselves, it gives them tremendous pride,” she said.

Provide feedback — Hadeed said it is important for leaders to provide good and bad feedback and she uses the “FBI Method,” which stands for Feeling, Behavior, Impact. The “FBI Method” was created by Bob Chapman, CEO of Barry- Wehmiller, as a simple test to get to the root of confrontation. “How did you feel when this person did whatever it was they did? What was that specific behavior that upset you? What was the impact of this behavior?” Hadeed said this method “is a way of getting feedback that inspires those who are doing great things to keep doing great things, and it inspires [lower performers] to change their negativity.”

Build relationships — A good leader will “check in” with team members and show concern about their personal lives. “No one can just drop what happens in their life and work, especially if it is something traumatic like a divorce or death in the family,” Hadeed said. One way leaders can make a personal connection with their team is by sharing how something in their personal lives shaped them. As her company grew, Hadeed said it became difficult to check in with all of her team, so she checks in with her executive team and her expectation is that they do check ins with everyone they oversee.

Make investments — Hadeed encourages leaders to identify peoples’ skills and help them develop those gifts by investing in them. Hadeed reminded attendees that while it can be discouraging to invest in people who might soon leave, “What if you don’t invest in people and they stay?” She added, “I realized that watching people grow professionally is the main reason I get up in the morning.”

The author is Internet editor of PCT.

It’s a statistic very familiar to those involved in the structural pest control industry: Termites cause more than $5 billion in property damage annually.

But it can be difficult for homeowners — unless they are among the unfortunate ones to have had their structures damaged by termites — to fully grasp the destructiveness of these minuscule insects, which measure ¼ inch or less.

The Professional Pest Management Alliance (PPMA), the public outreach arm of the National Pest Management Association (NPMA), has addressed this longstanding industry challenge head on with the Tiny Termite House, a groundbreaking study and video project that revealed the destructive nature of termites as never before.

Released in May, the Tiny Termite House video has been picked up by dozens of local and national news outlets (see related story, below), helping PPMA achieve its goal of educating consumers about the dangers of termites and giving them a better understanding of the importance of working with a licensed pest control professional.

AN IDEA IS BORN. Scientists and pest management professionals have long understood termites’ destructive capabilities. And while the pest control industry has had success in getting the word out about termites and termite damage through traditional marketing, PPMA believed there was room to grow consumer awareness about termite dangers.

PPMA wanted to create a campaign that would best utilize present-day marketing tools and strategies. “In order to engage today’s consumers, you have to make science fun and interesting, and it has to be visual because everything is so visual these days,” said Cindy Mannes, executive director, PPMA.

So, PPMA actually “thought small” for a big marketing campaign. “The germ of the idea was: How about if we build a three-dimensional dollhouse and set termites loose and see how it goes?” Mannes said. “It kind of grew from there.”

In fall 2017, Mannes approached the PPMA Board of Directors, which loved the potential of this project to raise consumer awareness about termite damage. Further, the board liked that the project provided PPMA investors added value by providing them with much needed termite photos/videos that could be used for marketing purposes (see related story, below). The board green-lighted funding for the project, with the goal of launching the videos in spring 2018.

IDENTIFYING RESOURCES. To make this project work, PPMA needed to find a specialized group that not only understood the science of termites, but could create miniature models and capture high-quality, professional video.

At an industry meeting last fall, Mannes talked to Mark Neterer, business leader, Dow AgroSciences Pest Management and Turf & Ornamental, who suggested she reach out to the New Orleans Mosquito, Termite and Rodent Control Board (NOMTRCB), a group with diverse talents that conducts field research projects.

At PestWorld 2017 in Baltimore, Mannes approached NOMTRCB Director Claudia Riegel with the idea. Riegel and her team enthusiastically agreed to take on this project. With the goal of releasing the videos in May, the NOMTRCB team had a tight time frame to make it happen.

Because winter was fast approaching Riegel knew termite collection would be the first item on her team’s “to do” list. “We have collection buckets buried in the ground all throughout New Orleans, and we were able to collect all of the termites we needed from one location — they were all Formosan termites,” Riegel recalled.

Since the project took place in the winter/spring time frame, great care was taken to house the termites in a climate-controlled environment. The termites were kept in a sandy soil that was misted to give the termites a water source. NOMTRCB Senior Entomologist Ed Freytag weighed the termites, which is where NOMTRCB came up with the 500,000-plus figure.

One of the NOMTRCB staff members with specialized skills is termite technician Shaun Broadley. While tracking termites is Broadley’s day job, his true passion is art. He was given the assignment and resources, and then was pretty much left on his own to create the dollhouse.

“My whole life I’ve always done different sorts of art with sculpture and wood, but I’ve never really done anything like this before,” he said.

Broadley’s initial research involved going online to look at a variety of model houses, including ones with floor plans. “Then, I looked at different building techniques, how they actually build houses, and I just tried to replicate that on a small scale.”

What Broadley and the NOMTRCB team designed was a miniature, two-story home that included many of the same features found in a life-size home, such as insulation, plumbing and electricity — and even added a moisture source to create the ultimate termite paradise. Like many American homes, the house was constructed on a cement slab.

Broadley tried to make the house as realistic as possible. For example, it is mostly constructed of pine boards (including the studs) because that is the wood most commonly used in U.S. home construction. Some of the finer details include windows and doors that open and close, polished hardwood floors, furniture and actual running water.

The project was a true labor of love for Broadley. “It kind of surprised me that everything I tried seemed to work — all the lighting, the running water, everything like that. I had all these ideas at first, but I wasn’t sure if they were going to work. I was surprised that it all came together, and I didn’t burn the house down with faulty electric wiring.”

BRINGING IT TO LIFE. The other critical component of this project was being able to capture quality, compelling video and photos. Fortunately, in Freytag and his assistant, Jack Leonard, the New Orleans Mosquito, Termite and Rodent Control Board has two of the best photographers/videographers in the pest control industry — both of whom have experience with macro- photography. The pair equipped the house with high-definition cameras throughout to study the termites progress from introduction to decimation.

Freytag and Leonard were tasked with capturing as much video as possible — everything from the construction of the Tiny Termite House to the house being eaten.

Having an entomology background really helps get pictures that tell the whole story, Freytag said. “If you don’t understand the biology, lifecycle and habits of your subject, it makes it a little more difficult to try to get the right pictures. With termites, you need to know what makes them tick and what doesn’t,” he said. “That helped us a lot because I think if somebody with no entomology background or no background in termites would have taken this project, I think they would have missed a lot of opportunities from not knowing what the termites were going to do.” For example, Freytag and Leonard were able to capture quality video of tunnel construction.

One of the techniques Freytag and Leonard used to capture footage was time-lapse videography. “It’s neat because you can take something that takes five hours or two days and compress it into a minute. And that’s what we did with a lot of the termite trail [footage] and when we released the termites on the house.”

At the end of every shoot, Freytag would review his best takes and send them to PPMA for use as B-roll.

A SCIENCE AND MEDIA SUCCESS. When it came time to turn the termites loose on the house, all of those involved in the project were eager to see what would happen. Would the termites behave differently in this new environment, or would they behave, well, like termites do?

“My initial thoughts were that the termites were going to cover the house in mud and not act like it was a house; they were just going to act like this was a bunch of wood,” said Freytag.

But to Freytag’s surprise they reacted to the model house as if it were a real house. “After we released the termites on top of the soil, they went into the soil and stayed for a couple days. Then after a couple of days, you’d see them trailing outside, on the foundation — which was a concrete slab.”

Freytag observed how termites found the wood components of the house and started building mud trails. “I said, ‘Wow, this is kind of neat because this is how you see them in a real house.’ Then we looked under the flooring, and they were attacking the floor joists, which is what they normally do. That was not expected because I just figured they were going to attack everywhere because it’s all wood.”

There were numerous other examples of how termites find vulnerabilities in a structure.

While the Tiny Termite House findings are of great interest to scientists, ultimately the general public’s response is what determines whether a campaign like this is successful. When it came time to launch the video, PPMA was ready with large-scale consumer media blitz. PPMA enlisted Jim Fredericks, chief entomologist for NPMA, as media spokesperson. In this role, Fredericks pointed out that “on the surface, the house appeared to be in good shape with minimal clues about the presence of termites. However, it was what was happening inside the walls and under the floors that showed the real story. This termite colony got right to work, forming mud tubes and turning this dream home into a danger zone.”

In addition to being picked up by numerous news outlets, the Tiny Termite House was a natural fit on social media, where short, captivating content rules. The video proved the perfect marriage of science and entertainment, and the best part was that the industry’s message of termite prevention and partnering with a licensed pest control professional was front and center.

The authors are managing editor of PCT and contributing writer of PCT.