Emerald ash borer takes on polar vortex: study

Winters on the Canadian prairies can be brutally cold, but researchers at Western University and Natural Resources Canada have found that even a freezing polar vortex poses little problem for the invasive emerald ash borer. A study published in the journal, Current Research in Insect Science , showed that overwintering emerald ash borer were able to survive during the polar vortex that hit Winnipeg and other parts of Canada and midwestern United States in 2019. During one experiment, they found that some individuals could survive even when their body temperatures dropped to -50 °C. The emerald ash borer was introduced to Michigan and southwestern Ontario in the late 1990s, causing major ecological and economic impacts, but work in that region suggested that the beetles would be killed by temperatures below about -30 °C. When an infestation was found in chilly Winnipeg, the team immediately wanted to find out how they survived. The research team, led by biology professor Brent Sinclair , first collected emerald ash borer from around Barrie, Ont., and they froze and died around -28 °C. "Barrie is as far south as we can get them in Ontario nowadays.