VANCOUVER, British Columbia (Reuters) - Cold temperatures did not stop the spread of pine beetles in Alberta this winter, and it may be too late to eliminate the tree-killing insects from the province, officials said on Thursday.
Cold winter temperatures slowed the growth of the beetle population in parts of the province, but a survey this spring indicates thousands survived in much of southwestern Alberta and in pockets elsewhere.
“Pine beetles may be here to stay in Alberta,” Sustainable Resource Development Minister Ted Morton said in a written statement, which also warned the province will have to work hard to keep the beetle population low.
Alberta has been attempting to stop the beetles in their spread over the Rocky Mountains from neighboring British Columbia, where they have devastated vast areas of forest over the past decade.
The tiny beetles, Dendroctonus ponderosae, lay eggs under the bark of mature lodge-pole pine and jack pine, eventually killing them. Once beetles infest a tree, it cannot be saved.
The insects spend the winter in the trees, so can be killed by periods of extreme cold.
The beetles now threaten the health of six million hectares (23,000 square miles) of pine forests in Alberta, officials said.
Reporting Allan Dowd, editing by Rob Wilson