The Southern Pine Beetle, smaller than a grain of rice, destroyed over 14,000 acres of pines in New Jersey in 12 months. Signature pine forests from New Mexico to British Columbia have been wiped out by the pine beetle. Montana lost 1,000,000 acres to the beetle in 2008, while Wyoming and Colorado lost 2,000,000 acres the same year. The largest known forest destruction by insect occurred in British Columbia when 33,000,000 acres of Lodgepole pines were destroyed.
A black, hard-shelled beetle drills through pine bark and digs a tunnel in the wood to lay eggs. The larvae hatch under the bark and feed on sweet cambium that provides nutrients to the tree. The larvae inject a fungus to stop the tree from moving sap. This fungus stains the wood blue. The fungi disrupts water flow to the crown of the tree, killing it. The tree emits a white resin into the drill hole to fend off the beetle, but the pines aren’t able to put out enough resin in drought conditions, so the beetle win the battle for life.
The Mountain Pine Beetle is the most important pine killing insect in western North America. Outbreaks of infestation destroy Lodgepole and Ponderosa pines. The life-cycle of the beetle is one year. To kill these beetles, there would have to be a severe freeze in early fall or spring while the insect was in the larval or pupal stage. The temperatures would have to be 30 degrees Fahrenheit below zero, sustained for five or more days. There are no labeled pesticides for use against the pine beetle.
The visible signs that pine beetles have invaded include hardened sap on the outside of the tree. There would be brown boring dust in bark crevices at the base of the tree. The eggs are laid in S-shaped forms along the burrowing tunnels that are packed with feces and bark dust. When the bark is pulled back from the tree, fine sawdust will fall out where the beetle has made her tunnels. Pines that have died and fallen to the ground due to infestation will soon have piles of sawdust along each side of the tree. While standing next to a tree that has fallen or to logs cut and stacked on the ground, one can hear the beetles burrowing inside the pine.
The Pine Engraver Beetle is only found in the state of Georgia in the Eastern White pines. The beetle is brown to black in color and measures .14 to 0.2-inches long. It has four teeth on each side of the rear. Signs that forests have been invaded include the yellow or red tree crowns noticed when the trees have died. White sawdust at the base of the tree indicates the presence of the beetles. The only measures that can be taken to control the beetle is the cutting and removal of infested and dead trees.
Pines most at risk of infestation are those that are weakened due to drought conditions and those that are overcrowded, receiving less sunlight. To protect pines on private property, an individual would need to inspect his trees on a regular basis. Pines that have been invaded should be cut down and removed so the tree can be burned with the adult beetles and any eggs or larvae inside.
Although there are several species of the pine beetle, the end result of an infestation is the same. The signs are virtually the same, as well. The crowns – top canopy of branches – turn yellow or rust red, indicating the tree is dead or dying. Sawdust behind the bark, tunnels filled with larvae and feces, and brown dust in the crevices of outer bark are all indicators of the presence of pine beetles. Peeling back the bark will reveal smooth groves or tunnels where the eggs had been laid. A loud clicking sound can be heard from the engraver beetle in the White Pines of Georgia. Cut logs from the dead pines will reveal streaks of blue from the fungi.
