The Upside to Cold Temps

January 31, 2019

S. Wold-Burkness, Department of Entomology

In a January 31, 2019 Pioneer Press article, Jeff Hahn state's that this cold snap is "definitely going to have negative effects on the emerald ash borer", with Rob Venette adding that it will "definitely help ash trees". Venette and Abrahamson have shown that winter mortality for emerald ash borer is definitely temperature dependent; the larvae can supercool to a certain point, but they die if they freeze, and there is variability in tolerance among individual insects. This is promising news, but at what point will they actually freeze? And what does supercooling mean? Do all bugs have this super power? Luckily there is an updated fact sheet "Tough Buggers: Insect strategies to survive winter in Minnesota" that will help explain these mysteries.