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.


The south­ern pine beetle is head­ing north to­ward Nova Sco­tia.

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