Ficus Fables

Aviva Lori
Send in e-mailSend in e-mail
Send in e-mailSend in e-mail
Aviva Lori

Today there is nobody who can remember when the sidewalks of Tel Aviv began to look like sweet, sticky compote. Tel Avivians aged 30-something don't remember anything else. They are convinced that the color of the paving stones was always dark purple or red with maroon blobs. The old-timers say - and today nobody believes them - that once the color of the Tel Aviv sidewalks was gray. Plain, dirty, boring gray, without colorful additions.

But it's not only Tel Aviv. In all the neighboring cities in that city's metropolitan area and along the coast, the situation is no different. The ficus and date trees that grow on the main streets and boulevards drop their ripe, juicy fruit onto the sidewalks and the roads, and there they pile up, layer upon layer, as in jars of preserves. The ficus fruits begin to ripen in March, and the season ends in late October; in other words, for most of the year the sidewalks of the cities are smeared with a sticky goo, a permanent and annoying nuisance for the residents. Anyone who lives in Tel Aviv or its surroundings knows that the plague of the ficus trees, a plague not mentioned in the Torah, is an inseparable part of the urban lifestyle.

An innocent stroll along Chen Boulevard or on Dizengoff Street in Tel Aviv always ends with a stiff brushing of the soles of one's shoes with hot water and soap. Bike and motorbike riders are in danger of slipping on the wet doughy mass that becomes oily, and car owners who are looking for a parking place in the shade know that they will find their cars the next day completely covered with the stains of exploded fruit and the remains of the nighttime festivities of the neighborhood bats. Do you want to live in a city in the Tel Aviv metropolitan area? To go to the beach on Saturday? To pop into a film/theater/restaurant midweek? The "dirt tax" is part of the deal.

The ficus is a very tall member of the mulberry family, which includes over 800 different species that grow in tropical and subtropical climates, in other words, in a hot climate such as ours. Most of the ficus trees are evergreens, and the first ones were brought to Palestine from India by the British in the 1920s. Until then, fig (ficus carica) and sycamore (ficus sycomorus) trees grew here; these are first cousins of the ficus. The fig tree existed in Israel already in ancient times: The biblical spies who were sent to tour the land returned with pomegranates and figs, and in 1 Kings (5:5) it says: "And Judah and Israel dwelt safely, every man under his vine and under his fig tree, from Dan to Be'er Sheva."

The British in India happened to enjoy the security and relaxation of sitting beneath their vine and fig trees, and believed that with a little effort, the new colony in the Middle East could become a tree-shaded Garden of Eden. Had they known that they would be here for only 30 years, they certainly wouldn't have worked so hard. The British left, but the ficus tree acquired citizenship and acclimatized beautifully, and at present about 70,000 of them grow here - 30,000 of which cause varying degrees of filth. There are 20,000 in Tel Aviv, and 5,000 of them create huge amounts of it.

Longing for the tree

The types of ficus that grow in Israel include the ficus religiosa or ficus sacra (bohdhi tree) - sanctified by the Buddhists, who believe that Buddha sat beneath it when he received enlightenment - the ficus microcarpa (green island fig), the ficus Bengali (banyan tree), the ficus obliqua (small-leaved fig), the ficus rubiginosa (rusty-leaved fig), the ficus benjamina (weeping fig), the ficus elastica (rubber tree) and so on.

What happened in the 1970s that turned the nice, broad ficus trees into a sanitation nightmare? In those days, a wasp one millimeter in length, whose life is meaningless without the ficus, immigrated to Israel. For dozens of years it had longed for the tree until it couldn't restrain itself any longer, hopped aboard the first plane and found a virgin paradise here: tens of thousand of ficus trees that for years had produced sterile fruit - little dry, green balls that fell to the ground quietly and without arousing any interest.

All that changed the moment the wasp landed here, which local botanists and gardeners discovered very quickly. Suddenly the trees filled with small, round fruit that were full of juice, fruits that fall to the ground in three to four annual cycles and dirty up everything in the neighborhood. The wasp's only function in life is to pollinate the ficus. As in a classical love story, for every type of ficus, there is only one (species of) wasp that is suited to it alone. The wasp actually lives in complete symbiosis with the fruit of the ficus. Its life cycle depends on the existence of ficus fruit in the area, and the ripening of the fruit, and its fall to the ground depends on the laying of eggs and the mating of the wasp inside.

How do they mate? "The ficus is the wasp's only host," says Haim Gavriel, the chief agronomist of the Tel Aviv-Jaffa Municipality. "They live a life of close cooperation. The wasp enters the fruit, lays its eggs there and from the eggs emerge larvae that develop in complete symbiotic coordination with the unripe fruit. Afterward the larvae turn into pupae, from which mature wasps emerge, male or female. The males immediately fertilize the females, and then break out and help the females that are imprisoned inside the flowers to emerge carefully, without breaking their wings. The moment the female wasp leaves, the male, which has now completed its function, dies. The female flies to a new fruit, lays eggs there and ends its life cycle. And thus the circle is closed. The hormonal activity that takes place in the fruit releases ethylene and other substances. Ethylene spurs the maturation process in the fruit and turns it into a ripe, juicy fruit, and the severing substances help it fall to the ground.

The big question today is how a tiny creature from Australia or Southeast Asia (the wasps' place of origin, as far as is known) arrived in Israel on its own. Since even today nobody knows for certain how the wasp managed to infiltrate the country, botanists and gardeners have begun to tell a number of legends that have been passed along. According to one of them, the wasps were brought by a researcher from the Volcani Center Agricultural Research Association (the research arm of the Agriculture Ministry), who visited Thailand and saw ficus trees loaded with ripe fruit and wondered why there was none on the trees here. He decided to research one type of ficus, the ficus microcarpa, but the sly wasps escaped and went on to other trees of that type, the most common in Israel, and pollinated them one after the other, thus multiplying by the millions. This story has been circulating among researchers, but nobody knows who the original scientist was and when everything happened.

By air or by sea?

Prof. Dan Eisikovitz of the department of botany at Tel Aviv University, doesn't believe this tale. He has another theory. For years he carried out theoretical research about the interrelationship between the ficus and the wasp, and among other things he tried to find out how the wasps came to Israel. One day he even took a few in a test tube and traveled with them to South Africa; he wanted to examine how long they could live in the cargo section. His student, Vered Schuster-Fichman, wrote her master's thesis on the connection between wasps and the ficus rubiginosa, which is native to Australia. They both believe that the wasp arrived here by ship.

"Up until 12 years ago," says Schuster-Fichman, "the rusty-leaved fig had no fruit, but then its wasp entered the country, and from that time it began to develop fruits that ripen. We tried to examine how this wasp arrived in Israel, and thought that perhaps it traveled in the cargo section of a plane. We checked the temperatures there and reached the conclusion that this was very unlikely, because they are too low. Our research indicates that the wasp arrived either by ship or in the pocket of a passenger."

Asked how such a small wasp can travel for so long by ship, Schuster-Fichman answers: "It can live for several days without food."

Gavriel, who focuses on the ficus nuisance every day, keeps close track of every scrap of information and research on the subject.

"There are several types of wasps," he says, "that have arrived in Israel during the past 30 years. How did they come here? There are all kinds of rumors, but I'm not aware of anything scientific. Insects and fungi can arrive in the pocket of a passenger or in a fruit that he brings with him. The wasps found excellent conditions here for developing here; the climate is suitable and they had no natural enemies that would reduce the population. We searched for a natural enemy in their native country, we wanted to raise it and disperse it so it would attacks the wasps. We discussed it with Prof. Zvi Mendel, a researcher at the Volcani Center, but he said that even if a natural enemy is found, and even if it kills some of the wasps, there will still be so many remaining that it's a wasted effort."

Agronomist Avigail Heller, the chief professional counselor for gardening and landscaping in the training and vocational service section of the Ministry of Agriculture, says that as far as she knows, the wasps came here from Turkey in the 1970s, concealed inside dried figs.

Solving the mystery of the sudden appearance of the wasps in Israel will not advance the war on the end result: the fruit. And the researchers have not yet risen to the challenge. There are lots of ideas, but still no results in evidence. Five years ago, Prof. Eisikovitz tried to organize a study on the subject. For that purpose he turned to the Tel Aviv municipality and submitted a research proposal that would have cost $62,000.

"I came to them with the project, at first I received no response, they had no idea what I was talking about; they sent me to the Center for Local Government, where they arranged meetings for me in the Kfar Sava Municipality. I asked for the minimum, only for research expenses. Afterward there was an argument about who would pay for it. I told them that their cleaning expenses are much higher than the sum I was asking for. In the end, four years ago we wrote a contract, Tel Aviv University signed it, and to date [the others] still haven't come to finalize it. Maybe they're waiting for me to come to them. Meanwhile I've retired and I'm continuing to work at the university as a free-lancer."

What did you intend to study?

Eisikovitz: "The interrelations between the ficus trees and the wasps, in order to find the weak points and to understand the life cycle of the wasp, and on that basis to begin to think, because otherwise it's hard to attack the problem. It's very complex, because the unripe fruit serves as food for hundreds of birds and bats."

But that's exactly the point, the bats are part of the nuisance.

"It's part of our ecological system in Israel. We can't just destroy what we don't like. I don't like sparrows, so will I destroy them? Science has already dealt with more complex things than this. If they invest money in it, a solution can be found."

`A huge nuisance'

Ruby Zlouf, head of the municipal beautification department in Tel Aviv, is meanwhile dealing with angry residents and doesn't quite know how to placate them: "It's a huge nuisance," he says, "one of the worst in the city, according to a survey of resident satisfaction. We wash down the streets with steam, but it's impossible to get rid of [the filth]. There have been incidents of motorbikes slipping on the roads, particularly after the first rain, when it turns into an oily, sticky and dangerous glop. It's a sugary substance that attacts flies and bats that really like the fruit - but their droppings fly onto windows, the walls of houses and cars. The ficus roots are so strong that they lift up sidewalks and roads, and damage sewers. The situation is especially difficult between June and October. We prune the trees, and that reduces the amount of fruit, but many residents ask us not to prune.

"On the other hand, I receive hundreds of letters from residents who write: `Leave us alone - go take the ficus trees and plant them in your own homes, or give them to someone else.' Another solution is uprooting them. But it's impossible to uproot the tree, because as I've mentioned, the roots choke the infrastructure."

Along with the many disadvantages of the ficus trees, they have many advantages. They are broad, their leaves are shiny and glistening, they are green all year round, their roots are strong, they don't need irrigation because they reach water sources on their own, they are easy to maintain, they have no pests. According to studies done at the Technion - Israel Institute of Technology in Haifa, the temperature in the shade of a ficus is three to four degrees (Centigrade) lower than any other shade.

"In terms of ecology, they do wonderful work in the city," says Zlouf. "They adsorb the soot. This is an amazing tree, it's a shame that it's impossible to separate the ficus from the wasp."

Gavriel, with two researchers, Eitan Pressman of the Volcani Center and Yitzhak Biran of the Hebrew University faculty of agriculture in Rehovot, sought solutions for the nuisance in the late 1980s - but didn't find any.

"We tried to uproot the ficus trees with all kinds of substances, and using all kinds of methods," says Gavrieli, "injection, infusion, treating the roots, spraying - but we had no practical results. The spraying reduced the quantity of fruit somewhat, but it turned out to be very complex and expensive. You have to bring tractors with cranes into the city center during the early morning hours, and spray several times a year. We wanted to do a study, but we wanted to involve other municipalities, so that the entire burden wouldn't fall on us. We turned to the Center for Local Government, but there were very few municipalities that showed interest and a willingness to pay for this research."

You didn't consider uprooting the ficus trees?

Gavrieli: "Uproot trees because of the dirt? That didn't even come up for discussion. The trees are protected. In order to uproot them we have to get permission from the Keren Kayemet Leyisrael [Jewish National Fund]." He rejects the accusations of foot-dragging in connection with Eisikovitz's study, and lays the blame on the Center for Local Government: "They didn't exactly cooperate with us, they postponed the matter, meanwhile Dan Eisikovitz retired, and it remains open."

In other words, stuck.

Low bat sorties

In Herzliya there are 2,000 ficus trees. "It's a little more, relatively speaking, than in other local authorities," says Moshe Fadlon, head of the city's beautification department. In the western part of the city, on President Ben Zvi Street, one can find one of the most beautiful ficus boulevards in Israel. The tall trees twist and turn, and create a natural covering on both sides of the street. One cannot take in the beauty properly with a quick glance from a passing car. But a walk along the sidewalks on foot is no great pleasure. The ficus fruit gets smeared and sticks to one's shoes, and it's quite hard to remove afterward. A walk on the street at night is more like a horror film starring Batman. Dozens of hungry bats fly above one's head, engaging in low sorties from side to side.

"Five years ago, we funded a Tel Aviv University study," says Fadlon. "They asked a number of local authorities for money for a study, but after we transferred NIS 35,000 to the Center for Local Government, we didn't hear from them again. Either the study failed or it's stuck. This week a company came claiming that it has carried out a pilot program in a number of small local authorities. They suggested that we do an experiment, too. I told them that I would turn to the municipal administration and recommend carrying out a pilot on 150 trees."

Aviram Cohen, spokesman for the Center for Local Government, said in reply: "Due to the fact that we didn't receive enough commitments from the local authorities to pay for the study, it won't be carried out. We received no budget whatsoever for carrying out the study, only promises to pay. The money that the Herzliya Municipality claims to have transferred to us is only a promise of payment."

The residents of Savyon also suffer from ficus trees. The fruit on the sidewalks is particularly annoying for those walking their dogs or jogging in the evening. Another problem in Savyon is the penetration of the roots into the yards and the blockage of drainage pipes. On two streets in particular, Hagiva and Har Dafna, the residents are disturbed by the plague of bat colonies covering the trees.

Romema Halevy, head of the local council, describes the two streets where the ficus trees are making a mess: "The walls of the houses get dirty from bat droppings. It is brown and sticky, and the walls look as though someone poured leftover coffee grounds on them."

In Savyon they are trying to use force to overcome the roots that penetrate the yards and the pipes. Wherever digging is done by the Israel Electric Corporation or the cable company, they install nets of one meter in width, which are supposed to block the roots and to prevent them from spreading. To get rid of the bats, they use a simple technique. They shine a strong light on them and the bats, which are nocturnal animals, flee from the rays of light.

"The residents complain bitterly," says Halevy, "but it's forbidden to uproot these trees; they're a protected species in Israel. Besides, removing the ficus trees from Hagiva Street would cost millions, because it would also destroy the fences surrounding the houses, the sidewalk, the curbstone and the road. We tried someone who injects hormones into the trees. The problem is that in our experiment it was only partially successful."

The Herzliya Municipality are fighting the bats with extra strong lighting, but as things look now, the bats are winning.

Ficus `birth control pill'

The initiator of the idea of injecting hormones is Moshe Shemesh, a 51-year-old agronomist from Moshav Ein Vered. Shemesh has an inventor's mind and has come up with the concept of microwavable heating bags (used instead of a hot-water bottle). In recent years he has been making a living by running election campaigns (working for Be'er Sheva Mayor Yaakov Terner, Labor MKs Benjamin Ben Eliezer and Avraham Shochat, and others). He became involved with the ficus trees out of desperation.

"In 1997, when Ehud Barak was running for head of the Labor Party, I was working at his headquarters and I would return home late at night. I lived in Ramat Gan at the time, and there was parking under a ficus tree. In the morning a disgusting sight would greet me. The car would be covered with bat droppings and black stains from the ficus fruit. My specialty is corn and wheat, not ficus trees, but I became ambitious and said that I wanted to study the subject."

Shemesh conducted research and also heard the rumors about the origin of the wasps. "The most common rumor is that the wasp arrived on a flight from Thailand on an El Al plane. That's strange - why should a wasp be on El Al? Maybe as a frequent flyer? An undercover agent? It's very unlikely that a wasp bought a ticket for El Al and flew from Bangkok to Israel. Apparently there was someone who brought it for research purposes. I heard that one of the researchers decided to investigate why the ficus trees were not bearing fruit, and a moment after you've brought the wasp, it's out of control. Its natural rate of increase is amazing."

At first Shemesh believed that the wasp had to be dealt with, and looked for pest-control substances. Afterward he understood that the wasp is very clever, and can quickly undergo genetic mutations that withstand the sprays: "That made me think that the only solution is to bring about a hormonal situation in which the tree won't produce fruit, and then I started to look for a `birth control pill' for the ficus trees, and arrived at a substance, a plant hormone, that causes the ficus not to become pregnant from the wasp. So it won't bear fruit."

In order to prove his theory concerning pregnancy and its prevention, Shemesh turned to the Ministry of Agriculture and the Tel Aviv, Savyon, Ramat Gan and Herzliya municipalities, suggested their cooperation and asked permission to inject hormones into the ficus trees within their city limits.

The ministry took up the challenge. Avigail Heller was appointed to examine the efficacy of injecting hormones, together with Shemesh. They chose an avenue of 70- and 80-year-old ficus trees of the microcarpa and obliqua varieties, at the entrance to Kibbutz Ein Shemer, and began the experiment a year ago. Shemesh injected hormones into 20 trees with triple roots. Into one-third of the roots he injected a strong dosage, in one-third a medium-sized dose, and into one third, which constituted the control group, he didn't inject anything. The experiment has just ended.

Shemesh is satisfied with the results; Heller less so. Shemesh says that he managed to reduce the amount of fruit by 80 percent. Heller says that at most he had a 50-percent success, and the trees shed too many leaves.

"In the ficus obliqua it was drastic," she says. "Entire trees shed their leaves. We found that the higher the hormone dosage, the fewer unripe fruits, but the fewer leaves as well. With the low concentration [dose], there was less shedding of leaves, but there was more unripe fruit. We didn't achieve a situation of zero fruit. We saw the same phenomenon in the ficus microcarpa: the higher the concentration the less fruit, but the more damage to the leaves, although it was less than in the ficus obliqua, maybe because the trees were huge. The experiment shouldn't be dismissed, but we have to continue to it. At the moment, it doesn't provide a solution. I still don't recommend using the substance."

Elite Magen of Ein Shemer, until recently in charge of landscaping in the kibbutz, recalls this beautiful avenue of ficus trees two decades ago, and claims that at the time there was no fruit as there is today - only small, dried-up balls that didn't bother anyone. Magen has mixed feelings about the experiment: "It turned out that several trees almost died," she said. "They lost all their leaves, and aside from that, there was no noticeable change for the better. On the other hand, several ficus trees really are bearing less fruit, but it is doubtful whether they will survive. Some of them have blossomed again, some not yet."

Shemesh says that this is only natural. Even when the birth control pill was invented, the first women who took it suffered from side effects. "The side effects taking place now in the trees that I am treating are similar to those that affected the first women who used the pill in the 1950s. For example, they grew beards, because at first there was too much testosterone in it. Everyone agrees that I've found the right substance, but at the moment I'm having a problem with the dosage."

Businessman Dudi Brimmer, owner of a senior citizens' home on President Ben Zvi Street in Herzliya Pituah, right beneath the ficus trees, was sitting in the garden one day, looking at the trees, the bats and the filth, and thinking of how to solve the problem.

"I was negotiating with several agronomists," he says. "They all said that there are studies, but that nobody has really looked into it. One day, gardeners came to my home in Shoham in order to prune trees, and I asked: `What does one do with the ficus trees?' And then they told me that some guy had invented something. I met Moshe [Shemesh] and we clicked. In terms of the business aspect, I liked the idea, and we established a joint company, Botanic, and then I stopped everything because I said that we need authorization from a public government body."

Brimmer registered a patent in the United States and in Israel, and is now working on registration in Europe. "Before submitting requests to register a patent, I carried out a comprehensive check all over the world, and discovered that there is no patent of this kind at the moment anywhere in the world, and that strengthened my belief in the chances of this product." n