Mountain Pine Beetle

Management of mountain pine beetle outbreaks: The good, the bad, and the unsolvable

 

References:

Carroll AL, Shore TL, Safranyik L. 2006. Direct Control: Theory and Practice. The Mountain Pine Beetle: a Synthesis of Biology, Management, and Impacts on Lodgepole Pine. p. 155-172. 

BC Government Mountain Pine Beetle Informational Website. Updated Feb. 2008. Accessed Mar. 6, 2013 from: http://www.for.gov.bc.ca/hfp/mountain_pine_beetle/bbbrochure.htm

 

Safranyik L, Linton DA. 1982. Mortality of spruce beetle broods in bolts submerged in

water. Journal of the Entomological Society of British Columbia. 79:8-11.

Photo Source: http://www.for.gov.bc.ca/hfp/mountain_pine_beetle/bbphotos.htm

 Word Count: 480

 

An effective management of the mountain pine beetles has yet to be discovered. Naturally, a long cold spell during winter can kill off the larva stages and control the population, however, with the ever increasing temperature and the shorter and milder winters, this population regulation is not occurring (BC Gov Website).  

Preventative control to minimize the spread of mountain pine beetles includes thinning pine stands; however, this tends to have a negative economic effect (Carroll et al. 2006). Direct control of beetle population involves attacking the beetles; there are three main direct control programs in place. These programs include (1) mechanical and cultural tactics, (2) chemical tactics, and (3) semiochemical tactics (Carroll et al. 2006). 

Mechanical and cultural tactics include fire, bark removal, and felling infested trees (Carroll et al. 2006). The first two tactics are only really effective when the infestation is small and contained in an area. Felling trees and processing them right away causes beetle mortality; however, if not processed right away the larva may survive and continue wreaking havoc. When testing methods for spruce beetle management the most effective mechanical tactic is falling the trees and submersing them in water for 6 weeks (Safranyik and Linton 1982). 

Chemical tactics include using a variety of insecticides, however, they currently are rarely used due to their toxicity to other insects and plants (Carroll et al. 2006). Semiochemicals are chemicals which act as pheromones and attract the beetles to certain locations. These tactics are generally used in mechanical tactics to kill the beetles (Carroll et al. 2006). 

Based on Carroll’s paper (2006) it seems as though the mechanical removal of the beetles appears to be most effective. However, the infestation is at a large enough scale that if these trees were all removed then this would have radiating effects on the entire forest ecology.  For example, as more pine trees die and are salvaged logged, more ground is exposed to precipitation. As talked about in class, this means there is increased melting rate of snow, increased erosion, and extreme variations in water flow (BC Gov Website).

So as it seems, our forests are hooped. How can we control this epidemic without destroying our water ways and forests? Another horrible part of these infestations is that the beetles prefer old growth pine trees, which we know houses many different species of animals and plants that are already at risk.