The Pine Beetle

Here we can clearly see a tree infested with beetles yet the canopy is still green. How can this be? One must know where in the lifesyscle of the pine beetle one is observing. It goes something like this… first we have a male pioneer that finds a susceptible host pine. He produces a pheromone attracting females. These females in turn lay eggs in galleries under the bark. Eggs turn into larvae larvae into nymphs and nymphs into young adults and young adults into mature breeding pairs again. The speed at which this occurs is based on temperature. In the summer months the entire cycle can be completed in 20 days or so, however, during the winter it might take 50 days or more. And there’s not a whole lot of activity that occurs below 55 degrees.

Trees store a lot more energy than they can consume, in fact over 60% goes to storage. We have 5 typical beatles here in the southeast, we have the black turpentine Beetle which usually attacks the base of the tree, then we have the southern pine beetle that attackes from about 4 feet above the ground upwards to where the branches start. And then we have three categories of Ips beetle. This Beetle likes any of the pine tree which is larger than 10 inch in diameter including large branches as well as the trunk.

In the video we can see that there are many pitch tubes along the trunk indicating that this was most likely a southern pine beetle attack because they canopy is still green. We can make the assumption that the attack happened late in the season severing the vascular system. Because the tree has so much stored energy and the temperatures have been cool the canopy has remained green. As the weather warms up however the canopy will quickly turn brown and die and the new adults will emerge from the bark to go find new trees to attack.