WINNIPEG — An invasive beetle that has already ravaged millions of trees in Central Canada and the U.S. has made its first appearance in the West. The emerald ash borer, a highly efficient killer of ash trees, has been confirmed in a tree in a Winnipeg neighbourhood. “At this point, we have to assume it’s as bad as it sounds,” said Krista Ryall of the Canadian Forest Service. Ash borers, originally from China, are already so prevalent in Ontario, Quebec and the eastern U.S. that scientists fear some species of ash may be wiped out. The International Union for Conservation of Nature has said the toll may eventually reach eight billion trees. “All of our North American ash species are vulnerable,” Ryall said.