New York Times
The streets of Buñol, Spain, will run red this week as 20,000 people hurl tomatoes at one another during La Tomatina, the world’s biggest food fight.
It’s a luxury that others envy.
Around the world, tomato crops are being ravaged by an invasive moth no larger than an eyelash. Originally from Chile, Tuta absoluta, also known as the tomato leaf miner, was introduced to Europe in 2006 via a container of infested tomatoes imported to Castellón, a Spanish province not far from Buñol. It spread throughout Europe, then to the Middle East, Africa and Asia.
The toll is particularly devastating in developing countries, where many farmers can’t afford integrated pest management (I.P.M.), the multipronged approach that has proved most effective at keeping the moth at bay.
Earlier this year, officials in northern Nigeria, where tomatoes are a staple, declared a state of emergency in Kaduna State, a major producer of the country’s tomatoes. By May, the moth had destroyed more than 80 percent of tomato crops in Kaduna; the price for a large basket of tomatoes rose to $212, from just $1.50 to $7.50 before the shortage.
At the peak of the outbreak, a Nigerian website published an article about Spain’s tomatofest headlined: “La Tomatina: 17 tomato photos that will make Nigerians cry ‘where is our God?’ ”
Though the leaf miner’s range in Europe is extensive, from Spain to Lithuania, many farmers have kept the moth’s numbers under control with an arsenal of specialized tactics. These include pheromones that lure the moths into traps or disrupt their mating; biopesticides based on bacteria, fungi or oils; chemical pesticides that are highly selective; and the introduction of the leaf miner’s natural enemies.
The last measure has been extremely effective in Spain, said Alberto Urbaneja, a professor at the Valencian Institute of Agricultural Research and one of the first to research the Tuta absoluta invasion in Europe. “If you can establish a good I.P.M. system based on biological control, it is possible to manage Tuta,” he said.
In countries with low financial resources, farmers often don’t take action until the pest has moved in. When it does, farmers turn to the pesticides they have on hand, which typically kill a broad spectrum of pests.
These chemicals are environmentally harmful and eventually lead to pesticide-resistant bugs.
In some countries, the problem comes down to a lack of technical knowledge or government support. With funding from USAID, Muni Muniappan, the director of the IPM Innovation Lab based at Virginia Tech, has been running workshops around the world to help farmers prepare for the inevitable spread of the leaf miner, which also attacks such crops as potatoes, eggplants and peppers.
Meeting the pest head-on “requires lots of training and information,” Dr. Muniappan said. But his work is currently limited to seven countries in Africa and Asia, including Bangladesh and Nepal, where scientists successfully caught the start of a Tuta absoluta invasion earlier this summer.
Experts say it’s only a matter of time before the moth invades the remaining countries within its geographical limits, including the United States, where the Agriculture Department has been monitoring Tuta absoluta and regulating the import of tomatoes since 2009.
The moths have a high reproductive capacity — each female produces up to 300 offspring in her lifetime — and they are small enough to be transported by wind, Dr. Urbanejo said. Their larvae devour tomato leaves, stems, fruits and flowers; uncontrolled, the pest can damage 100 percent of a crop.
Nevertheless, with the right combination of methods, countries should be able to keep the moth at manageable levels, Dr. Urbanejo said.
The problem is already showing signs of stabilizing in some African countries, including Kenya, where the moth was first detected in 2013. Farmers there are starting to use pheromone lures and adaptive practices like alternating tomatoes with other crops, said Fathiya Khamis, a scientist at the International Center of Insect Physiology and Ecology in Nairobi.
At least one company in Kenya, Kenya Biologics, now sells pheromone traps locally, and Dr. Khamis’s team is looking into other options as well, like fungal biopesticides and specialized nets.
As farmers adopt more sustainable strategies, tomato lovers may ultimately have to adjust to higher prices. Still, the drastic price hikes that initially accompanied outbreaks have settled down. In Kenya, tomato prices rose to $1.25 a kilogram after the moth outbreak from just 60 cents. Now, prices hover around $1. Tomato prices are now just slightly above what they were before the outbreak in Nigeria as well, said Orode Doherty, a doctor who lives in Lagos.
As for La Tomatina, its organizers say it is not contributing to tomato shortages; 145 to 160 tons of wild tomatoes are grown in western Spain just for the festival. These tomatoes aren’t cultivated, harvested or processed as they would be for human consumption, said Miguel Sanfeliu, a representative at La Tomatina.
“It’s like growing trees to make confetti for a party,” he said.
An earlier version of this article misstated the number of countries in which Muni Muniappan has been running workshops to help farmers prepare for the inevitable spread of Tuta absoluta. It is seven, not six.