Mountain pine beetles throw scientists for a loop

Did December’s cold snap do the trick and diminish the pine beetle population? Only time will tell. 

Even though the mountain pine beetle is only between 4 and 7.5 mm in length, it is an incredibly destructive little pest. Destroying hectares of mature lodgepole pine forests across North America, the mountain pine beetle, or dendroctonus ponderosae in Latin, is a pesky little insect that can survive even in extreme cold.  

Alberta Sustainable Resource Development is in charge of pine beetle control in the province. According to Erica Lee, senior forest health officer, they are “right now in the middle of the survey and control portion” of the program.  Even though Parks Canada is in control of the area around Jasper, the two organizations will compare data.  

Given the bitterly cold weather over the past few weeks, many people would expect the mountain pine beetles to perish. However, the bugs “produce a glycol, or an antifreeze,” said Lee and “they fill themselves with the glycol, so they’re able to withstand the cold temperatures.”  

Final mortality rates will not be reported until the spring. Currently, “we do have some areas where we do have (population) increases but relative from last year we’ve got a decrease so far,” said Lee.  

Lee not only attributes the relative decrease in the pine beetle population to the cold weather, but also to management programs. There is “zero tolerance” for the pine beetle, said Lee, and “once we have our sites identified, we do our survey and control work... we go out and we ground survey these sites and then we go back in and control the infected trees.”  

Relying on a mortality model developed by Barry Cooke of the Canadian Forest Service, Sustainable Resource Development will compare the field data with the modeling data once winter tallies are in to determine the provincial mortality rate for the winter.  

The management program is for both the short and long term. In the short-term, explains Lee, they rely on destructive control.  “We have single tree fall and burn. If the tree is lightly hit, you can just peel” away the infected portions. There are no chemicals used in the control process. “We also do use mechanical control,” added Lee.  This involves tree chipping and harvesting of infected stands of pine.  

The long-term plan, said Lee, uses “fire and harvesting to reduce the long-term susceptibility of the forest.  So we’re working with timber companies to reduce the amount of susceptible trees on the landscape over the next 20 years.”

Similar in principle to the FireSmart program which reduces forest density to curb the spread of fires, the mountain pine beetle management initiative also endeavours to reduce the forest’s thickness to prevent the spread of these destructive insects.