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Prof uses science to solve problems for Ontario growers and developing nations

Story by Lori Bona Hunt / Martin Schwalbe

From left: Asma Hanif, Mark Fenske and Anne Ferry
Rebecca Hallett

U of G professor Rebecca Hallett always wanted to be a scientist. Growing up, she explored the outdoors, collected insects, entered science fairs and never balked at the bulls’ eyes, sheep brains and other specimens that her physiologist father stored in the refrigerator. But she didn’t want to be just any scientist. She wanted to be the kind who makes science simple and practical, the kind who uses know-how and discoveries to help ordinary people help themselves.
It was a philosophy she developed early and solidified during a research trip to India as a university student. There she saw how problems that might seem insignificant to Westerners could harm people’s lives and livelihoods. She also discovered that simple, affordable science could make a tremendous difference. Since then, she’s had little interest in research purely for the sake of knowledge.
“I want what I do to have practical use,” says Hallett, a Guelph environmental sciences professor since 1998. “I’m more interested in how people can make use of the information. I want to use science as a way to help solve problems.”
A specialist in plant-insect interactions, invasive species and pest management, Hallett is especially interested in finding solutions to reduce reliance on insecticides. Her latest research combines science and practicality to help Ontario’s soybean producers deal with an invasive pest that threatens the industry: soybean aphids (Aphis glycines). She has developed a smart phone application that helps farmers decide quickly and easily whether to spray to control soybean aphids, based on the prevalence of natural predators.
It works like this. In the field, a farmer looks for insects and consults a smartphone application to see whether the bugs are natural enemies of the soybean aphid. The app includes high-quality colour photographs of aphid predators like lady beetles and parasitic wasps. After counting the numbers of predators and aphids on a random selection of soybean leaves, the farmer punches in the numbers.
In crunching the numbers, the app accounts for everything from the pest-predator ratio to the changing weather. It then tells a farmer whether to spray or not, or whether to wait and test again in a few days.           “If there are enough natural enemies in the area to keep the aphid population down, no spraying is required,” Hallett says. For example, one lady beetle can eat up to 100 aphids in a day.
Knowing whether it’s time to spray is crucial, because it’s not economical for growers to spray more than once per season; acting too soon or too late is no good. Soybean aphids, though tiny in size – less than 1.6 mm – and nearly translucent, can do a lot of damage. “So you want to time it properly if you have to spray,” Hallett says. “And if you don’t have to spray an insecticide, it can help protect the aphid’s natural enemies.”
Without enough lady beetles and other predators, soybean aphids can overwhelm plants, causing premature flower drop, stunted stems and fewer seeds. Prolonged exposure to dense aphid populations can lower crop yields significantly – by 50 per cent in some places. In 2004, the tiny pests managed to wipe out a significant chunk of eastern Ontario’s soybean crop.
That’s worrisome because Ontario grows about two million acres of soybeans annually, three-quarters of Canada’s total production. The crop has also become a critical agricultural export for Canada, worth well over $1 billion annually.
Insect damage is a fairly new concern for Canada’s soybean farmers. “Historically, soybean farmers didn’t need to worry about too many insects, but then Aphis glycines came along.” Originally from Asia, the invasive aphids surfaced in North America in 2001 and soon made their way into Ontario.  
Farmers have been counting natural predators to help determine whether to spray their fields for the past several years. But until now, the process required a lot of hands-on calculations, usually while sitting at a desk. “Now they never need to leave the field. The app does all of the calculations, behind the scenes. It’s very user-friendly,” Hallett says.
The app debuted in the fall; farmers may download it free at: It’s currently available only for the BlackBerry, but Hallett hopes to adapt it for other devices.        She’d also like to include site-specific temperature forecasts and other details such as whether nearby farmers had opted to spray. Ultimately, she hopes the app will stress the powerful role insects can play in controlling soybean aphid populations, and reduce or even eliminate insecticide use.
Hallett worked on the app with environmental biology PhD candidate Christie Bahlai, B.Sc. ’05 and M.Sc. ’07, and alumna Tracey Baute, B.Sc.(Agr.) ’95 and M.Sc. ’99, who is now a field crop entomologist with the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA).
Funding came through the Knowledge Translation and Transfer program, a new initiative under the University’s partnership agreement with OMAFRA that supports the application of research results. “I’m interested in helping growers address issues,” says Hallett, especially when nature can help out.
Hallett studied botany and biogeography  at the University of Toronto before heading to Simon Fraser University for graduate studies in entomology and chemical ecology. For her graduate research in Indonesia, she devised a natural way to help deal with coconut rhinoceros beetles (Oryctes rhinoceros) and Asian palm weevils (Rhynchophorus ferrugineus) that were wiping out palm trees, damaging the economy and spreading to other parts of the world.
“In the United Arab Emirates, people had no idea the infestation was happening until there was a wind storm and their date trees fell over,” Hallett says. She devised a mass-trapping program using pheromones to lure both types of beetles. Her research led to mass production of synthetic versions of the pheromones, which are now sold all over the Middle East and Southeast Asia.
As an undergrad, she worked in India to help mustard seed and oil seed producers solve pest problems. She returned there before beginning graduate school and had hoped to go back after her studies. But after Indonesia, she came to Guelph. Years later, she runs a research lab with about a dozen students and post-doctoral researchers.
She plans to return to Southeast Asia and to her palm weevils during her next sabbatical, and hopes one day to resume international development-related research.
She’s influenced by the parting words of a scientist she met in India. “He said to me: ‘Rebecca, go and do your graduate work and then come back and help these people; they need you.’ That has stayed with me.”

Historical Note: Soybeans were first grown in Canada in the mid-1800s, with growing trials recorded at the Ontario Agricultural College in 1893. They became a commercial oilseed crop in Canada after a crushing plant was built in southern Ontario in the 1920s.

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