by Bill Bradley
Aside from being blamed for the increase in violent storms and intense heat waves, global warming may also be affecting the ability of the forests to handle pest outbreaks.
"I can't say for certain the pest outbreaks, like the jack pine
budworm outbreak near Capreol, are related to global warming,
but we do know the jack pine budworm is killed by severe winter
weather," says Al Keizer, forest health monitoring officer with
the Canadian Forest Service office in Sault Ste.
Marie. 
"After all, after it molts six times, it over-winters as a very
small larvae just under the bark of the host tree. Milder
winters mean more survive and that may mean they overwhelm
natural predators and diseases."
He says jack pine budworm is on the increase in the Greater
Sudbury area. "New expansions of jack pine budworm were
detected this year along Highway 69 near Britt. As well, new
defoliation and populations were seen east of Killarney towards
the French River, around Agnew Lake and near the towns of
Falconbridge and Wahnapitae."
Another pest that seems to be able to survive the milder
winters is the gypsy moth, said Kathryn Nystrom, an insect
identification officer with the Great Lakes Forest Centre.
"Extreme conditions of prolonged cold (-30 degree Celsius) can
also kill unprotected eggs," she wrote in a 2001 paper on gypsy
moths.
The oak ridges to the south of the city have been ravaged by
gypsy moth. In June, Northern Life reported gypsy moth damage
from Azilda to New Sudbury.
"The European gypsy moth is of concern because of its voracious
appetite and its capability of feeding on both deciduous and
coniferous trees. After repeated infestations the tree may die,
or become so weak that it becomes susceptible to secondary
infestations from other pests," wrote Nystrom.
Others pests are also moving north.
One such example is the emerald ash borer, a highly destructive
insect that kills ash trees. The pest feeds on the inner bark
of the tree, preventing the transfer of nutrients up the trunk.
Its thought to have arrived in the United States from Asia in
solid wood packing material and was first found in Detroit
Michigan in 2002. More than 20 million ash trees in Michigan,
Ohio and Indiana have died, according to a Michigan State
University website.
The emerald ash borer showed up in Windsor in 2003. Several
counties in southwestern Ontario are being regulated to
restrict the transfer of infected wood to other areas. Surveys
for the pest are now taking place in northeastern Ontario
because it's moving northwards.
"We're doing tree inspections along the Highway 17 and Highway
69 S. corridors, especially around lodges and cottages, because
emerald ash borer has been spotted in Brimley Michigan across
from the Sault," said Keiser.
There are other pests, some new and some familiar, to be
concerned about, Keizer says.
"The hemlock looper has been devastating in the Fort Francis
area, exploding to 10 times its normal infestation area,
killing hemlocks in as little as a year. We are seeing it in
Capreol, Espanola, and Nickel Center, Falconbridge and
Wahnapitei. Again, if the weather is conducive to its survival,
this insect population explodes with dire consequences for the
trees infested. Then there is the wood sirex, a deadly wasp
recently found along the St. Lawrence River. We will be putting
out traps for that one too along the Highway 17 corridor," said
Keizer.
