Thousands of small test tubes were set up in neatly organized rows in the cupboards of Armand Séguin’s laboratory. Soon, the scientist would be filling them up with sap squeezed from the bark of ash trees. Séguin has been studying cancer for more than two decades. Now he’s turned his expertise to stopping the spread of the destructive emerald ash borer, a green metallic-looking beetle that is smaller than a fingernail. The Laurentian Forestry Centre in Quebec City is one of five federal research hubs in Natural Resources Canada’s Canadian Forest Service. …Robert Lavallée, a scientist and an emerald ash borer specialist at the centre is working on a solution to fight the emerald ash borer in cities like Montreal, and in Ontario forests. A specific Canadian fungus had caught his attention — it could get inside the pest and kill it.