Science has gained a tactical advantage in the war against the mountain pine beetle (MPB).
Over several years of reconnaissance and laboratory analysis, a team of young researchers at the University of Northern British Columbia (UNBC) recently uncovered some of the complexities of the insect’s highly survivable physiology.
In September, as the beetles were advancing deeper into Alberta after pillaging vast tracts of pine trees in B.C., the researchers published a study revealing in greater detail how MPB larvae resist the extreme cold of winter.
“Prior to this, other than one of the anti-freeze compounds being known, and a few other facts, we didn’t really have this grand, global view of the inner workings of an overwintering pine beetle larvae, and now we do,” said Dr. Dezene Huber, an ecosystem science and management professor at UNBC, also the principal investigator in the study.
Like a spy satellite, the research team surveilled overwintering MPB larvae in lodgepole pine trees at numerous infested sites for several months.
When the operation came to a head, the larvae were captured live, loaded into vials, covered in dry ice and transported back to the university laboratory.
It was in the lab where the research team extracted new proteins – encoded as genes in the beetle’s DNA – from the MPB larvae that are known to make anti-freeze compounds, which help prevent internal ice formation and, ultimately, mortality.
“Before, we could make guesses about what might be going in the MPB and which genes might be involved, but now we know specifically which genes are likely involved in overwintering,” said Dr. Huber.
Meticulously detailed and laden with scientific terms, the study is expected to assist governments, industry and scientists intercept future MPB infestations by relocating management infrastructure to areas of prime concern, Dr. Huber explained.
“Say one group (of MPB) is spreading into a new area,” he said.
Considering prevailing weather conditions in the region, “in theory, with a bit more work, we can pinpoint specific genes that are being activated in that population, or how those genes differ from similar genes in another population,” said Dr. Huber.
Similar to a military operation, the discovery of the proteins will serve as vital intelligence in the ground war on the MPB, a menacing insurgency that is now capable of traveling over rugged mountain ranges to get from one region to the next.
“If you have the information on the enemy and where they’re strong and where they’re weak, you can focus in on the appropriate parts of the enemy’s formation,” said Dr. Huber.
Aside from pesticides, however, there isn’t a “magic bullet” that can be used to strike the MPB dead, Dr. Huber explained.
Even if humans did possess a chemical spray, for example, raining it over millions of hectares of forests wouldn’t be practical. Furthermore, the compound would have to infiltrate the forest canopy and penetrate tree bark in order to kill the beetle, all while minimizing collateral damage.
“It would have to be done on a tree-by-tree basis,” Dr. Huber theorized.
The MPB is incredibly resilient. When fully prepared for winter beneath the bark of a tree, larvae can withstand temperatures of almost -40 Celsius for days and sometimes weeks at a time.
More troubling is how the beetle is responding to climate change: developing faster, laying eggs sooner, invading foreign territory and attacking trees at higher elevations and latitudes.
According to a study published in March 2012 by the University of Colorado, evidence of climate change is indisputable, and in some areas MPB larvae are redeveloping twice per year rather than once.
“The expansion of the MPB into previously inhospitable environments, combined with the measured ability to increase reproductive output in such locations, indicates that the MPB is tracking climate change, exacerbating the current epidemic,” the report says.
What’s worse, as beetle-ravaged trees turn a parched red color and die they release enormous amounts of carbon dioxide into the atmosphere, 990 million tons already in B.C. alone.
The aftermath is an altered forest ecology that begins contributing to global warming rather than combating it, according to the report.
Historically, early cold snaps in the early fall or late spring, and prolonged frigid temperatures during mid-winter have kept MPB populations in check, but the occurrence of these events are increasingly becoming less probable each year, Dr. Huber explained.
“A cold harsh winter is sort of something to write home about lately,” he said.
Although weather plays a critical role in stunting the reproduction of MPB larvae, drought, past land management practices and landscape characteristics – especially large concentrations of mature lodgepole pine – can also facilitate the full-scale infestation of certain areas.
“It’s really no one particular cause,” said Dr. Huber.
One afternoon at the height of the infestation in the Prince George area in 2005 or 2006, Dr. Huber recalls working at a tree improvement station when he was overrun by a swarm of mountain pine beetles that were in the midst of attacking a tree.
There are even stories of swarms being detected by radar at the Prince George airport.
“It’s a very impressive force of nature,” said Dr. Huber.
“However, impressive natural phenomena can have devastating economic and environmental impacts… and the reality is, there are a lot of people, families and jobs that have been affected.”