Temperature and plant hardiness zone influence distribution of balsam woolly adelgid damage in Atlantic Canada

Abstract

Management of balsam woolly adelgid (Adelges piceae Ratz.) and of trees damaged by this pest may pose one of the biggest challenges to forest management in Atlantic Canada during the next decade. Feeding by the balsam woolly adelgid is restricted to Abies species in which it causes gouting, branch and upper crown death. Approximately 100 years after its introduction into eastern Canada, symptoms of feeding by the balsam woolly adelgid on balsam fir are found throughout all of Nova Scotia, most of Newfoundland and in southern and eastern New Brunswick. The distribution of symptomatic balsam fir trees coincides with areas where mean January temperatures are below -11°C and where plant hardiness zones are higher than 4a. The presence of balsam fir trees with obvious symptoms of BWA damage throughout much of Atlantic Canada emphasizes the ubiquitous presence of this pest in these provinces and highlights the need to develop hazard rating systems to establish pest management programs to diminish its impact. Key words: global warming, Adelges piceae Ratz., forest insect pest management, abiotic factors