Pine-hungry beetles creeping north
Warming trend makes pine bark more palatable
Global warming is fuelling the northward migration of pine hungry beetles, according to researchers from Columbia University.
Over the next few decades, increases in winter temperatures could significantly extend the range of the southern pine beetle, one of the world’s most aggressive tree-killing insects.
Their journey north will see the beetle established in Nova Scotia by 2020, said Corey Lesk, the lead author of the study and a graduate student at Columbia’s department of earth and environmental sciences.
The study points to “huge vulnerability across a vast ecosystem,” Lesk said in a news release.
“We could see loss of biodiversity and iconic regional forests. There would be damage to tourism and forestry industries in already struggling rural areas.”
Until recently, southern pine beetles lived from Central America into the southeastern United States. But in recent decades they began appearing in parts of the northeast and New England.
The beetle’s range has been sharply limited by winter lows in
the northern U.S. and southern Canada. But the coldest night of the winter has warmed by roughly 3 C over the past 50 years at weather stations across the United States, according to the Columbia researchers.
This warming trend makes pine bark more palatable for the southern pine beetle, a reddish brown or black insect about the size of a rice grain.
The researchers say minimum air temperatures will rise by 3.5 C to 7.5 C across the northeastern United States and southeastern Canada by 2050 to 2070.
The provincial Department of Natural Resources declined an interview because staff weren’t familiar with the study.
“That said, we are aware of the negative effects of pine beetles and our forest protection branch works to ensure our forests are protected from pine beetles and other pests,” spokeswoman Krista Higdon said in an email.
If this infestation indeed occurs, the southern pine beetle would join other voracious insect species that have destroyed countless trees over the years in Nova Scotia.
The brown spruce longhorn beetle devastated parts of Point Pleasant Park in 1999 into the 2000s, and spread to Victoria, Kings and Lunenburg counties. And the beech leaf mining weevil chomped its way through beech trees in Halifax in 2012 and also turned up in Lunenburg County.
On top of the current predictions about the southern pine beetle, woodlot owners have been warned about the hemlock woolly adelgid, an aphid-like insect that kills hemlock and spruce trees.
Woodlot owner Jim Crooker said the Canadian Food Inspection Agency has confirmed the presence of this tiny white pest, which sucks the sap out of the trees. To date, the adelgid has been found in Digby, Yarmouth and Shelburne counties.
“And that’s same kind of thing (in that it’s) working its way north because of supposedly climate change,” Crooker said in an interview from his home in Queens County.
“Any bug infestation in that way is about the same; it’s not a good thing,” said Crooker, a board member of the Woodlot Owners Association of Nova Scotia, who has 365-hectares of natural forest in South Brookfield.
The biggest impact on woodlot owners during any infestation relates to restrictions on moving wood, he said, even if the insect hasn’t appeared in their area.