Lessons On Peace From The Common House Fly

This article is more than 7 years old.

Richard Pollack told this story live before an audience at the Oberon in Harvard Square on August 27, as part of a Story Collider event sponsored by WBUR. The Story Collider features true, personal stories about science.

It was a very early, quiet Sunday morning, some two decades ago in Boston. I was a postdoc in the laboratory of the late Andy Spielman at the Harvard School of Public Health. We studied things like mosquitoes and ticks and lice, and the things they transmitted.

Joining us that early morning were two scientists, one each from Jordan and Israel. They were sent on a mission by their respective governments — a very odd mission of scientific diplomacy. House flies had become a tremendous problem, a shared common enemy throughout the region. The flies had become incredibly abundant on both sides of the Dead Sea, likened to a latter day plague of biblical proportions.

How bad, really, could a few house flies be? Let me paint a mental picture that comes from experience. On the Israeli side, there were resorts that lined the border with Jordan. At check-in during fly season, the desk clerk would hand you a key, a postcard of the hotel, and, sometimes, a fly swatter. If you were silly enough to walk outside with a cup of tea, within seconds the first house fly would dive bomb into your beverage. This would be followed almost immediately by a hailstorm of others, with the result of a crust of flies forming on the surface. If you were still outside after a few minutes, your arm would be wet because the fly bodies were displacing the liquid within your tea.

As you might imagine, this distressed a lot of people. They complained to the hotel managers as if they were somehow responsible for the problem and could do something about it. This made everybody angry and ate into profits, as a lot of rooms were left vacant during the season.

The complaints were heard. They were heard all the way up to Jerusalem and then, amazingly, to Washington DC.

In each hand, the author holds about a thousand house flies, caught in one of the hundreds of traps set by the researchers in Jordan and Israel. (Courtesy)
In each hand, the author holds about a thousand house flies, caught in one of the hundreds of traps set by the researchers in Jordan and Israel. (Courtesy)

Now, for every house fly that one might encounter in Israel, there were impossibly more in Jordan. How bad were they? Trying to converse outside was a very dangerous act. Simply opening your mouth was the opportunity for one or several flies to find an opening. It wasn’t unusual to see folks spitting, gasping, coughing, and then running inside. In Jordan, fewer people were complaining about the problem, but there was one particularly influential one. We were told that Queen Noor was displeased with the flies and she had asked, or instructed, her husband to do something to fix this. He asked around and then he, too, contacted some folks in Washington DC to complain.

What would account for all of these flies? Why had they become so abundant? Once on the wing, where did they go? How far did they travel? What directed them? How did they navigate? These are all questions that excite and engage the scientist. Everyone else just wanted some sort of solution to the problem, of course. But before we could come up with the solution, we had to understand the answers to all of those questions.

So, this was the reason for this meeting — this secret and very quiet meeting. Except it wasn’t so quiet. The two scientists joining us that day were incredibly distrusting of each other. Remember, there was no peace accord between these two countries, they were enemies of each other, but they were here because they were on this sanctioned mission. They were arguing with each other, they were incredibly disagreeable, they could only agree to disagree. We were at a stalemate.

At one point, our Israeli colleague repeated the party line: The Jordanians were somehow growing billions and billions of house flies and programming the things to fly across the border to create a pestilence across the land. Our Jordanian colleague was incensed by the allegation, or so he made it seem. He allowed that some of the flies might indeed come from Jordan, but, he wondered, why would a perfectly happy and healthy Jordanian house fly want to go to Israel in the first place?

Andy and I didn’t know whether to laugh or proclaim failure on the spot.


As this discussion was going on, it was incredibly heated. We had a small square table that the four of us were sitting around, and every time either the Israeli or Jordanian fellow made a statement, they pounded on the table. With every pound of the table, and there were many, the table wobbled, and wobbled excessively in a distracting manner. In unison, these two fellows turned to us and asked, “Why do you have such a crummy table? Can’t you afford something better?” And then, the worst, “Is this a reflection of the quality of Harvard science?”

As Andy and I were trying to conjure up some sort of apology, we saw the two of them, under the table, eye to eye — one of them lifting the table, the other shoving a wedge of paper under the short leg, to steady this rocking problem that we had. Success! Scientific collaboration and cooperation. It was amazing, our very first success. Would it be our last? Time would tell. But this act had rebooted the conversation, and we went on for hours to discuss the scientific issues and so forth. We didn’t even want to break for lunch or dinner.

At the end of this time, we had a draft document that we turned into a proposal for USAid. They took the bait and funded several years of field work for us. So that was success No. 2. Armed with the money, we traveled to the Middle East, to the fly-plagued and politically charged border. At every stop we went to, folks came out to welcome us with open arms (Well, their arms were out, but I think a lot of that was them swatting the flies out of the way). They expressed their wishes for us, and their expectations that we would solve their problem.

"It was incredibly hot in the shade, and there was no shade at all. We also had to watch where we stepped. There were minefields all around us, or at least that’s what the signs said."

The flies also greeted us, and in much greater numbers. Looking at the flies, we couldn’t tell from where they came. They weren’t waving Israeli or Jordanian flags, they weren’t wearing yarmulkes or keffiyehs, and we couldn’t tell if they were buzzing in Hebrew or Arabic. So we had this problem — we needed to find out where they were. So we went on a hunt.

We visited sites in Jordan and Israel and very quickly found major fly factories. In Jordan, there were nascent fields of peppers and other vegetables as far as the eye could see. In each field, there were dense arrays of plastic irrigation hoses and over each hose for the entire length — they go on forever — was a layer of dried chicken manure, which is a very readily available and inexpensive fertilizer. It is also, once it becomes wet, an incredible fly-rearing medium. Amazing numbers of flies were produced. With every handful of the compost that we examined, on average there were 500 flies developing at any spot.

It was a tremendous number of flies. And that was constantly going on, through the crop-growing season.

Fields in Jordan produced huge numbers of flies. The black plastic sheets cover irrigation hoses coated in chicken manure, a powerful fly-rearing medium. (Courtesy)
Fields in Jordan produced huge numbers of flies. The black plastic sheets cover irrigation hoses coated in chicken manure, a powerful fly-rearing medium. (Courtesy)

In Israel, there were flies produced en masse as well. But in this case it was from the agricultural success and excess. Vegetables were so plentiful that any imperfect fruit had very little resale value. These were just tossed aside in these ever-growing pyramids of fruit and vegetables left to rot in the sun, with the help of millions and millions of house flies.

With this, there was a realization from both sides that they each were at fault in producing massive numbers of flies. This helped tone down the rhetoric a bit — another success. And now we knew where many of these flies were coming from. The next questions were: Where do they go? How far do they go? Can we track their movements?

We embarked on a study to do that. We set out arrays of traps. Each trap could catch 50,000 to 60,000 flies or so. And each one was baited with the most god-awful swill. How do you attract flies? With honey of course. So this had sugar water, yeast and rotting fly bodies. And no matter how careful we were to carefully decant the swill into each of the traps, it would invariably slosh all over us. No amount of soap and water could wash the stuff out. I think I can still smell it to this day.

We could catch lots and lots of flies this way. Once we had them, we would paint them by the millions with fluorescent dyes and then do the unimaginable and release them. Massive clouds of flies would take to the air. We would then activate an array of traps — our Israeli and Jordanian colleagues would start monitoring their traps on each side at various distances, every 30 minutes or so thereafter — so that we could track this moving wave of flies. This was another bit of success, because the only way to accomplish this was with really close scientific collaboration.

Now, this kind of work would be difficult enough to accomplish here in New England. But we were in the Dead Sea area. It was incredibly hot in the shade, and there was no shade at all. We also had to watch where we stepped. There were minefields all around us, or at least that’s what the signs said and we were not about to question those.

To make matters worse, our Jordanian colleagues and their families were accused of cooperating with the enemy, the Israelis. This simply redoubled everybody’s efforts to work cooperatively and toward a common goal — that being to prove the other guy wrong.

What did we learn from all this? Many of the Jordanian flies seemed to seek asylum in Israel, and many Israeli flies must have thought the grass was greener over in Jordan. What made them go in either direction, and such distances — many of these flies went tens of kilometers in just a few hours — is another question for another research project.

So we learned that flies traveled very far and invaded other countries. But beyond the scientific discoveries, of which there were many more, the level of cooperation was absolutely amazing. Our colleagues from Israel and Jordan would call each other — this was before the peace accord was signed — and they would speak about things other than flies. Once peace broke out in the region, families from each side visited each other, attended weddings and other social occasions, and were best of friends for many many years thereafter.

From USAid’s perspective, they didn’t really care that much about the science. It was the cooperation and the talking that was really the goal, and this was a huge win for them.

From my perspective, I learned a lot as well. I learned not to get so stressed out when the best ideas — these interventions that we came up with — were not readily embraced by the farmers and the local officials. But that happens. Change in the Middle East takes generations (and that’s generations of people, not flies). I also learned to keep my mouth closed, particularly during fly season. But that helps in many ways. It helps with the listening and thought processes.

Most importantly, I learned to embrace wobbly tables. The smallest distractions can sometimes lead to the most profound discoveries.

I wish you all a very good conversation around wobbly tables.

Richard Pollack is a public health entomologist serving government and academia — the Harvard School of Public Health and Boston University. He is the founder and CEO of the consulting venture IdentifyUS.

Listen above to Pollack telling his story in front of a live audience at the Oberon Theater in Harvard Square. The Story Collider returns to Cambridge on September 23 at the Middle East Downstairs.

This program aired on September 11, 2013. The audio for this program is not available.