Despite a frigid winter that killed many of them off, destructive mountain pine beetles continue to thrive in Alberta and could spread farther east.
Field surveys show low temperatures last winter and fall killed off most of the bugs in the mountains and foothills of southern Alberta, but new swarms of the tree-killing insects are expected to fly into the area this summer from British Columbia.
In northeastern Alberta, more of the tenacious beetles survived the cold and have hatched new offspring that could now fly east through a band of boreal forest.
“These results show we need more than cold winters to be successful in our fight against the pine beetle,” Ted Morton, Alberta’s minister of sustainable resource development, said Tuesday.
The province plans to continue cutting trees and setting controlled forest fires to try to contain the threat posed by the beetles.
Alberta spent $55 million fighting the beetles last year and has already earmarked more than $10 million for this year.
More funding is expected to come after crews determine how many new bugs the province is dealing with and where they have flown.
The black beetles, which are about the size of a grain of rice, have already ravaged more than eight million hectares of lodgepole pine forest in B.C.
They have an internal anti-freeze system that allows them to withstand frigid temperatures, but are susceptible to extreme cold snaps in the fall and spring or when winter temperatures fall below -35 C for a number of consecutive days.
A fungus the bugs carry actually kills the trees, changing the colour of the needles from a healthy green to a rusty red.
The destruction wastes valuable timber and creates an eyesore that can deter tourism. Dead stands of pine also alter watershed ecosystems, which can affect fish and wildlife, change spring snow-melt patterns and cause flooding.
Scientists are worried the mountain pine beetles may eventually spread east into Saskatchewan and beyond. They could then possibly start destroying the jack pine forests that stand across much of the country.
“We do realize that this is likely a long-term battle, not a short-term battle,” said Erica Lee, a spokeswoman for Alberta Sustainable Resource Development.
Officials admit the best hope for killing off the bugs remains probably rests with Mother Nature. A few years ago, two successive frigid winters wiped out the bugs in the Chilcotin area of B.C.’s central interior. But the population survived in others areas of the province where the temperatures weren’t as cold.
“A lot of what happens with the mountain pine beetle will depend on the weather,” Lee said.