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 “colony collapse disorder” responsible for the deaths of millions of bees worldwide.
Gray said his longtime 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 behaviours. The results could have major effects on agriculture.
Gray’s flight simulator is like a videogame for insects. The device has allowed Parkinson to study how the locusts’ ability to detect and visualize objects changes 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 videogame!” Gray said.
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.
The reaction time of locusts treated with the pesticide slows down, impairing their ability to avoid objects for as long as one day after treatment, Parkinson said.
“This is a serious problem. Locusts’ behaviour seems 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,” Gray said. “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.
Federica Giannelli is a graduate student intern in the U of S research profile and impact unit.
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.