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Virginia Tech News / Articles / 2018 / February 

Countries get heads up about leafminer invasion thanks to Virginia Tech

March 7, 2018

Crates of tomatoes in Nepal.

17 Crates of tomatoes in Nepal in 4 stacks.
Crates of tomatoes in Nepal awaiting shipment.

Virginia Tech researchers have created a modeling system that tracks the tomato leafminer along trade routes, enabling warnings to be issued for the first time to countries bracing for invasion by the pest that threatens tomato crops worldwide.

Through the modeling system, researchers showed that the insects spread in Nepal along the trucking routes of tomato shipments. The models not only showed that food-transport systems are linked to the new incursions, but also demonstrated the role of humans.

Muni Muniappan, director of Virginia Tech’s Feed the Future Innovation Lab for Integrated Pest Management, funded by USAID, said the new research provides key details about the spread of pests. Muniappan’s lab, in concert with Virginia Tech’s Biocomplexity Institute, developed the technology to track the travels of the tomato leafminer, Tuta absoluta, by looking at people’s role in transporting the insects as tomatoes move from field to market.

“Human activities – like carrying infested materials on airplanes, ships or vehicles – are instrumental to how pest invasion occurs,” said Muniappan, who sounded the alert on the worldwide “tomato emergency” in 2015, a year before the leafminer destroyed 80 percent of Nigeria’s tomato crop.

The tomato leafminer’s next strike is expected to be into Southeast Asia. The Virginia Tech lab’s two awareness-creating workshops in Cambodia in 2016 provided tools to farmers, policymakers, and scientists bracing for the invasion.

The research team that created the modeling system included mathematicians, computer scientists, a physicist, economists, and entomologists working to analyze the flow of Nepal’s tomato trade.

Abhijin Adiga, research assistant professor at the Biocomplexity Institute, said that worldwide efforts to achieve food security must include how foods are moved to market. “A framework such as ours can be quickly extended to other crops, livestock, pests, and regions with minimal effort,” he said.

The new model might be of use to other industries as well, such as improving food flows and transportation logistics, he said. Though centered on Nepal, the research can also be adapted to other countries and pest invasions, such as a stink bug invasion that has reached Europe, he said.

Tuta absoluta is native to South America but was accidentally introduced to Spain in 2006. Now, it plagues Europe, Africa, the Middle East, and Central and South Asia. Muniappan and other experts say it has the potential to wipe out 100 percent of the crop’s yield. The pest, which renders tomato crops pockmarked and discolored, is also attracted to eggplants, sweet peppers, potatoes, and other plants. It has no known effective natural enemies and surmounts geographic and climatic barriers.

The Feed the Future Innovation Lab for Integrated Pest Management, with eight projects in seven countries in Asia and East Africa, has executed dozens of projects across the globe since 1993. It takes a transdisciplinary approach to fighting global hunger, employing research in fields such as entomology, plant pathology, and computer science.

The Integrated Pest Management Innovation Lab is a project of the Office of International Research, Education, and Development, part of Outreach and International Affairs.

Written by Sara Hendery

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