Cold Mortality of Emerald Ash Borer

1. Cold Mortality of Emerald Ash Borer Emily Johnson

2. Emerald Ash Borer • Accidental introduction • Asian origin • First discovered in 2002 and has spread since • Death of millions of ash trees • In the epicenter of invasion in MI, more than 99% ash mortality

3. As of this month, where are they?

4. Could extirpate one North America’s most distributed tree genera

6. EAB Risk

7. Scientists from the University of Minnesota claim that the extreme cold from the polar vortex (1/1/2014-1/9/2014) may delay spread of EAB and cause high levels of mortality • Predictions • 0°F: 5% Mortality • -10°F: 34% Mortality • -20°F: 79% Mortality • -30°F: 98% Mortality

8. Data Collection • Selected 8 states with high risk and within the polar vortex zone • Estimated EAB spread from 2006-2014 • Estimated EAB Risk • Selected 91 dispersed counties to gather minimum temperatures for • Interpolate weather data • Convert minimum temperatures into % mortality

17. Conclusions • Areas where greatest dieback would have occurred mostly don’t have known, established EAB populations • Most likely had some positive impact • Southern WI may experience greatest benefit