Arborist Forum:Observations on EAB and winter's arctic blast

摘要

Subzero temperatures were widespread across the central and northeastern United States from Christmas through the first week in January 2018. Frigid temperatures from time to time are not all that unusual for eastern Iowa. What set this cold blast apart from the others was its severity and persistence. For nearly two weeks, we saw minimum temperatures well below zero. Dubuque recorded double-digit lows on five of those days, reaching 21 below on New Year's Day.Being an inquisitive retired city arborist, I saw an opportunity when we returned to more seasonable temperatures. Within two blocks of home while returning from an ice-fishing outing, I spotted my old crew removing an ash tree heavily infested with emerald ash borer (EAB). That facilitated my opportunity. Dressed for the occasion, I pulled over and began removing the bark from limb sections the crew provided me. With the string of frigid temperatures, including that low of 21 degrees below zero, I wascurious if it had been cold enough to kill any larvae beneath the bark.