Hello Bark Beetle, Bye-Bye Pine: How Weakened Pencil Pines Fall Prey to Bark-Boring Bark Beetles
The Italian Cypress, also known as pencil pine, makes a fine privacy tree for outdoor areas and swimming pools. A row of these narrow but tall and elegant pines, which grow up to 40 feet tall, can provide wind protection, sound reduction and privacy, all while adding a touch of class to a landscape. However, bark beetles such as the five-spined bark beetle are also quite fond of pencil pines. This is bad news because bark beetles are voracious eaters. An outbreak of bark beetles on Mount Diablo in California caused the deaths of 29 million pine trees.
Bark beetles in Australia are found in the pine growing regions of Queensland. That means homeowners with pencil pines as part of their landscaping should regularly inspect their trees. Although bark beetles prefer to attack tree stumps and dead tree roots, they are also partial to trees that are weakened due to stress.
Weakened Trees are Susceptible to Bark Beetles
Italian Cypresses that have been weakened by heavy drought, rain or nearby construction may attract the attention of hungry bark beetles. Once bark beetles discover a weakened tree, the males tunnel their way inside and attract more beetles by releasing pheromones. This is bad news for the tree and any other weakened pine trees in the area as the tree may be quickly overwhelmed by the sheer number of beetles boring into it.
They don't stop at one tree. Should the other pencil pines in your privacy hedge also be weakened, they too will be eaten from the inside out.
Stressed Pine Trees Exhibit Outward Symptoms
Though it could be years before a traumatic event such as a drought begins to take its toll on a pencil pine, when it finally does, it will become noticeable. Sick and stressed pine trees begin to brown in the middle. This is the tree's way of preserving itself. In order to survive, much as deciduous trees do, a pine will deprive portions of itself of nutrients and water.
If you see this beginning to happen, check the ground around the tree. Too much moisture can cause root, and not enough water will cause the pine needles around the middle to brown. Examine your trees to ascertain the problem and then provide a solution as quickly as possible before bark beetles show up to wreak havoc.
Although bark beetles are only 3-5mm in size, a large number of them will finish off a weakened tree. If one or more of your trees has been invaded by bark beetles, call an arborist and have them remove the affected tree before the bark beetles turn it into a lifeless but nonetheless dangerous husk. Otherwise, the next big storm may bring the structurally weakened tree crashing down.
If you have dead or rotting trees on your property, hire a tree removal service so you can dispose of the at-risk trees and better prevent bark beetles from invading your property and attacking otherwise healthy trees.