[Fly Control] Making a Difference

You may not know the flies’ name but you know what they are. You’ve seen clips on television of African children with flies buzzing around them; often they land near the children’s eyes.

The fly, Musca sorbens, is a regional fly that is a vector for trachoma disease — an infectious eye disease that is a leading cause of blindness and is especially prevalent in Kenya.

Pest management professional John Dunbar took it upon himself to try to help these children and their families with this public health pest by traveling to Kenya and spending 10 days on the ground trapping, baiting and treating the flies. He says he didn’t accomplish much on his trip — but anyone who knows about his story knows that isn’t the case.

FINDING THE RIGHT CAUSE. John Dunbar, technical director, Terminix Service, Columbia, S.C., was formerly a medical entomologist in the U.S. Navy Reserve while employed with Terminix. He worked on numerous vector-borne disease and preventive medicine projects and those Navy experiences led him to seek out a volunteer project using his entomology background. He has a master’s degree in entomology from Clemson University.

Dunbar wanted to use his skills as a pest management professional and donate his time and expertise to protect public health somehow, somewhere. But he didn’t know how, when, where or even what he was going to do. "What I wanted to do, it was difficult, because no one can talk the ‘bug language,’" he said.

"I was naïve," he continued. "Medical people go all over the world and do amazing things, but the scale of pest management doesn’t lend itself to doing that." Additionally, while there are numerous medical and religious service missions already established and well organized, there are no such groups serving the pest management industry.

Dunbar made countless phone calls, visited websites, and talked to anyone he could to try to determine what pest control-related service project he could contribute to. But all of his networking efforts didn’t turn anything up.

"Finally I just got to the point that I decided I just better go build houses, I can’t make it happen," he said. "I had given up."

Then, as often happens when one door closes, an opportunity came from an unexpected source.

"I went in to do my taxes and was talking to my accountant about what I was trying to do," he said. Amazingly, his accountant had a friend who was headed to Africa that summer with a non-profit group. "I just called them up and they said ‘Come on, do what you want to,’" he said.

The group, the Maasai American Organization, is a small non-profit organization that promotes education and community health in the Siana Group Ranch in the Narok District of Kenya. While there wasn’t a pest control component established with this group, Dunbar now had a framework within to work. "This organization had done a lot of good stuff," he said.

FLY RESEARCH. Once he secured the opportunity and knew where he was headed, Dunbar researched everything he could get his hands on about the biology and habits of Musca sorbens, the fly he was going to encounter across the Atlantic.

Unlike the common housefly, Musca domestica, M. sorbens breeds primarily in human, cattle and animal excrement. Adult flies feed on human and cattle secretions of the eye, nose and mouth as well as any secretions from wounds or sores and thus spread the disease.

There was virtually nothing in the literature about M. sorbens so he made some calls and did some legwork to find out who did know about it.

"We were meeting and he mentioned this project and asked me if I knew anything about this fly. I had never heard of it," said Dr. Bob Cartwright, Syngenta Professional Products. "So I asked some folks in Syngenta’s Basel, Switzerland, office since there we had a number of people who had had a lot of Africa experience with malaria products. They were able to send a little info on the fly and had some conversations about what product do you think would work around structures, reduce populations, etc."

With the information from Switzerland now in hand, as well as a few tidbits he’d found on his own, Dunbar then designed a fly control program he thought would work in Kenya. He decided he would try as many things as he could and incorporate liquid perimeter treatments and monitoring with fly traps, as well as some baiting.

Dunbar previously had worked with Bayer Environmental Science on a fly control program that he thought may be applicable to what he would encounter in Africa. "Part of this plan came from a treatment program Terminix did for an intense account," he said. That project involved baiting and perimeter treatments and "what we did worked well.

"That was in the back of my mind to almost duplicate it there," he said. "I didn’t know much about this fly so it was a place to start."

Dunbar called on suppliers he thought could lend a hand with his perimeter/monitoring/baiting plan: Bayer Environmental Science, Central Life Sciences, Rockwell Labs Ltd and Syngenta Professional Products. (See related article on page 84.)

"I’ve known these suppliers for years, I know about their products and I know how they work," he said. "And of course all of them were very generous and very helpful and gave me the materials to work with."

The Trip to Africa. In July 2008, Dunbar took two weeks of vacation from Terminix and traveled by himself for his first trip to Africa. Leaving the comforts of home behind, he landed in Nairobi and then traveled by bus about 100 miles to the village. "It took eight hours because the road and the transportation were poor," he said.

When he arrived at the 1,000-person village, he met with members of the Maasai American Organization. Volunteers, including medical and pharmacy college students, were already there, many of whom had been working with this particular village for a long time. "It’s like Christmas when the volunteers get there," he said. "They’re all friends."

The village was made up of a couple miles of plains where the villagers grow their food, including rice, beans and peas. There was a church built by missionaries long ago that served as the base of operations. The village also consisted of mud huts with dried cow dung roofs. The villagers rely heavily on cattle in their lives, making their bedding from cow hides on wood frames of twigs and limbs.

One of the biggest issues facing the villagers is the lack of clean water. "If they need water in the middle of the night, they walk barefoot to a spring and rely on gravity to bring the water to them," Dunbar said.

When Dunbar arrived in Kenya, the village was doing no fly control of any kind. In his first few days, he would often see 100 flies with him in one hut.

FLY TREATMENT. Since Dunbar’s trip was during the July dry season, he knew right away this wasn’t the ideal situation for his treatments "This fly is not prevalent in July," he said.

Once he started performing inspections and treatments (see treatment article on page 80), he realized how difficult it was to tell M. sorbens and M. domestica apart. "When I got there I said, ‘Geez, they look exactly like house flies to me. In the field, I can’t tell one from the other," he said. Unfortunately, however, there was one telltale behavior — M. sorbens fly in the corners of people’s eyes.

"I walked between the compounds, down the trails, setting up trapping, some with baits, some with lures, just to see what I could get," he said. "I had good results with some, not so good with others. I probably tried too many things. I wanted to see if I could hit on something."

As his program continued, the villagers were grateful for Dunbar’s work. Fly monitoring collections made after liquid perimeter treatment contained many fewer flies compared to the numbers being caught in the days before treatment. Residents noticed almost a total lack of flies after treatment and were thankful for the respite.

Final thoughts. "There were no great accomplishments in any of this," Dunbar said about his trip. But just because he didn’t rid the village of flies or come up with a complete treatment plan doesn’t mean he didn’t accomplish something. Simply by telling his story he may inspire other pest management professionals to share their talents in similar ways. But unfortunately, there’s no central resource PMPs can turn to for such volunteer opportunities.

"I really believe there are a lot of people who would want to do something like this" but there’s no way for them to connect with one another, Dunbar said.

As for his 10-day trip, Dunbar said it was "a great experience, the adventure was phenomenal, photography was amazing, and I pretty much did it all for the price of a plane ticket.

"On the way home, I felt great, but I didn’t feel like I accomplished anything. But I went and I tried to do something," he said. "Maybe something else comes out of it by somebody else."

The Maasai people were kind, appreciative people, Dunbar said, and they’re dealing with "every kind of issue on the planet just to survive.

"It’s amazing — there’s a lot of bad stuff going on and yet for them, life is good. They don’t know about TVs and material things. They know what life is like for them and they make the most of it."

The author is editor of PCT magazine.
 

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What Others Are Saying About John Dunbar’s Work

"John is a humble guy to a fault. I know we often focus on at-home issues with different PCOs but this is something different. (John is) trying to give back to society in a way that transcends what the pest management industry is doing already."

— Ray Daniels,
Bayer Environmental Science Field Sales Representative

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"We were glad to help John out and pleased that he could fulfill his desire to carry out this type of work. I have worked with some organizations in the past, though never with an individual on this type of project. I think it’s great that John took it upon himself to carry out this project."

— Cisse W. Spragins,
Rockwell Labs Ltd

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"This was really a wonderful thing John Dunbar did and we all should try to make time to do these sorts of things, especially globally, to do more pro bono work. He’s a good man."

— Dr. Bob Cartwight,
Syngenta Professional Products

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"You normally don’t hear of this kind of thing. I was kind of amazed when he mentioned it to me and I said to him, ‘John, what do you want to accomplish here?’ and he said ‘I don’t know. I just feel like I can bring some help to these people, and could add to their comfort by helping with these flies.’ I thought it was a great opportunity for the pest control industry and I commended him for taking his time and his expertise to share with someone else. I think it was great."

— Charlie Pate,
Zoecon Mid Atlantic Region Manager

 

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Evaluation of Management Techniques to Aid in the Control of Bazaar Flies

By John Dunbar

The objective of this exercise was to determine if commercially available fly baits and attractants could be used successfully against Musca sorbens, a primary vector of Trachoma in Africa. We also wanted to evaluate commercial fly trapping devices and perimeter applications with pyrethroid insecticides.

Even though M. sorbens is closely related to M. domestica, its habits are distinctively different. It breeds primarily in human waste exposed on the soil surface, a key factor because the Maasai people do not use latrines and defecate on the soil surface. This fly also breeds in cattle or other animal excrement but to a much lesser extent. The larvae feed and develop in the feces and the adult fly emerges several weeks after eggs are laid. Adult flies feed on secretions of the eye, nose and mouth as well as any secretions from wounds or sores. They feed on these secretions from humans and cattle and transmit the disease from person to person. The bacteria that causes Trachoma also survives in rags and clothing exposed to secretions and is readily transferred, especially between children. Sanitation in the Maasai community is poor. There is no running water or power, making personal hygiene difficult.

The flies are very similar in appearance to M. domestica. They have to be identified under a microscope and even then it’s difficult to separate the two. Fortunately they are easily identified by their behavior. They move much more slowly than the housefly when disturbed and they rest for long periods in the corner of the eye while feeding on eye secretions. They rarely enter structures, including latrines. The use of enclosed latrines would be a great aid in controlling this fly.

Fly populations in this part of Africa fluctuate between wet and dry seasons. M. sorbens and M. domestica are present throughout the year but the ratios are very different depending on the time of year. M. sorbens is predominate in the spring and fall while M. domestica predominates in the early to mid summer. At the time of this project, M. sorbens numbers were at a low point. Because they are easily identified by their unique behavior on the host, we were able to determine that they were present.

THE TREATMENTS. Two family compounds inside the village of Losho, Kenya, were selected for the evaluations. Various traps and baiting stations were installed on a number of mud huts inside the villages. These devices were hung from roof supports on the exterior of the structures at varying heights ranging from about 2½ to 4 feet above the ground. All trapping and baiting was initiated on July 4, 2008, and catches were evaluated on July 7. Estimated numbers of flies were recorded for each device.

On July 8, liquid perimeter applications were made to the exterior walls from approximately 4 feet up to the roof line, which was at about 6 feet in order to coat fly resting areas. Roughly 10 gallons of diluted Demand CS with iCAP technology insecticide was applied at label rate of 1 ounce per gallon of water. A total of 10 huts were treated, each of which measured approximately 400 square feet. New traps were installed after treatment in order to compare catch numbers before and after treatment. On July 10 (48 hours after treatment), the catches were evaluated to estimate the reduction of fly populations after treatment.

Zoecon’s Terminator Fly Attractant was able to attract some M. sorbens but more work is needed to determine how well it works when larger populations are present. The other baits and attractants deserve more testing too as they may prove effective when M. sorbens is in higher numbers. Most captured flies appeared to be M. domestica but very few were actually keyed out under a scope. While this is disappointing, it is still of value because we were very successful in trapping house flies, which are mechanical vectors of several diseases. Some researchers think that houseflies are also capable of transmitting Trachoma. Traps and baits could be incorporated in a control program and could help reduce housefly populations dramatically. People living in the areas baited reported that fly numbers were much lower after two days of trapping.

Zoecon’s Fly Terminator Pro reusable traps containing Terminator Fly Attractant was the most effective trap we used on both flies. All traps worked better when placed in locations exposed to the afternoon sun because flies prefer a warm resting surface. Catches were bigger near doorways, and since flies travel with the people or their animals, it makes sense that there would be more flies near doorways. Another very effective attractant on house flies was Invite Fly Gel Lure by Rockwell Labs. It was applied to glueboards suspended from wood roof supports.

One of the newer products tested was Maxforce Spot Fly Bait by Bayer. It was applied as a liquid to cardboard squares about 1 foot by 1 foot and they also were suspended from roof supports. The squares were hung on cord instead of being stationary and the wind motion kept flies from lighting. The product did very well indoors, totally reducing house fly populations quickly. One other very effective product was Golden Malrin used in an Apache Fly Bait Station. It attracted and killed large numbers of flies but all appeared to be houseflies.

While baits and attractants may offer some interesting possibilities, it is the use of effective liquid insecticides that offers a realistic opportunity of reducing fly populations to a significant enough degree to potentially reduce the occurrence of Trachoma in a village such as Losho. Demand CS insecticide proved to be very effective in reducing fly populations in both compounds where it was used. Collections made 48 hours after treatment contained very small numbers of flies compared to the numbers being caught in the days before treatment. Residents noticed almost a total lack of flies after treatment. This is significant for both species because they share the same resting areas and when they rest on a treated surface, they are exposed to a lethal amount of insecticide.

A program using pyrethroid insecticides such as Demand CS could be effectively used and has already been demonstrated to be effective in several locations in other parts of Africa. Additional areas, such as animal holding pen timbers, would have to be treated. A year-round program would probably require at least 120 gallons of material to treat all 12 compounds in Losho to do one application. Total applications per year might be in the neighborhood of 30 with some months not requiring any treatment and some months requiring weekly treatment. There are a lot of variables involved and these numbers are best guess assumptions. It could take 200 gallons per application and more than 30 treatments per year might be required, which would drive costs up. It also could be determined that ½ ounce/gallon is effective and cut the cost in half. An interesting possibility would be the partnering of Maasai American with companies such as the ones mentioned here.