Student studies pesticide effects with flight simulator

By Federica Giannelli and Lee Bonham

This article first ran as part of the 2016 Young Innovators series, an initiative of the U of S Research Profile and Impact office in partnership with the Saskatoon StarPhoenix.

Virtual reality consoles are a big deal in gaming, but they could also be the next breakthrough in biology research.

Rachel Parkinson, a University of Saskatchewan biology master’s student, is using a virtual reality flight simulator to study how a nicotine-based pesticide, called imidacloprid, is affecting locusts even at non-fatal doses. This neonicotinoid pesticide is among the most commonly used in Canada.

“There is a lot of controversy over these pesticides,” said biology professor Jack Gray, Parkinson’s supervisor. “They are used on a large scale because they are considered safer than other pesticides, but many recent studies like Rachel’s show that it is more complicated.”

Parkinson’s results suggest that the pesticide may affect an insect’s ability to visually detect moving objects such as trees and predators, and possibly play a role in the bee “colony collapse disorder,” responsible for the deaths of millions of bees worldwide.

Gray said his long-time understanding of locusts’ vision and flight steering could be used to study the pesticide’s impact on at-risk pollinators such as bees, which have more complex social and flying behaviors. The results could have major impacts on agriculture.

Gray’s flight simulator is like a video game for insects. The device has allowed Parkinson to study changes in the locusts’ ability to detect and visualize objects when they are dosed with the pesticide.

“I thought how I could get a 3D, immersive environment that an insect could move through, and I said, well, a video game!” said Gray.

During his post-doctorate in Tucson, Arizona, Gray modelled the simulator’s software after the 1995 video game Descent, a space ship shoot-em’-up and an early precursor to 3D gaming.

The simulator works much like old rear projection televisions, but instead of a flat screen, images are projected onto a curved dome that sits in front of a tethered locust.

Once the locust is in the simulator, images of looming objects and trees are projected onto the dome, immersing the insect in a virtual world that it can “move through” and “explore.”

By using a small electrode in the insect’s thorax, Parkinson measured the electrical signals directly from a neuron in the insect’s nervous system that detects visual motion and controls flight.

In locusts treated with the pesticide their reaction time slows down, impairing their ability to avoid objects for as long as one day after treatment, she said.

“This is a serious problem,” said Parkinson. “Locusts’ behavior seem to be affected by the pesticide, even at very low doses.”

Gray said now he would be interested in testing the pesticide’s effects on bees using non-fatal doses.

“We don’t have as much information about bees’ ability to detect and avoid moving objects in motion as we do for locusts,” said Gray. “But if we applied our previous research using the same techniques, we could do similar experiments on bees.”

Funded by the U of S and the federal agency NSERC, Parkinson has presented her findings at conferences across the world.

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