Pine Tree Beetles

Pine trees, belonging to the genus pine of the family Pinaceae, are evergreen coniferous trees that have needle-shaped leaves. About 115 species of pine are identified from all over the world. Pine trees are distributed widely, especially in the cold climatic conditions. Some species of pines are adapted to extreme cold areas, where snowfall occurs in more than six months a year.

The barks of pine trees are usually thick and resinous. In addition to the needle leaves, a mature pine tree exhibits another scale leaves that are brown and on-photosynthetic. Almost all the varieties of pine trees exhibit a characteristic shape and/or canopy. Hence, they are usually planted for designing the landscape and other decorative purposes. Commercially, they are also grown for timber, wood pulp, resin and other valuable products.

Pine Tree Problems: Beetles

Though pine trees are hardy in comparison to other decorative plants, they are susceptible to certain diseases and pests. Some of the common diseases of pine trees are sapsucker damage, needle blight, tip blight, gall rust, fusiform rust and root rot; whereas, devastating pests include beetle, sawfly, scale, spider mite, nematode, moth and weevil. If not controlled in the early stages, these pine problems can be devastating. Following are some of the common pine tree beetles.

Sawyer Pine Tree Beetle
Sawyer pine beetles are one of the most damaging pests. It indirectly causes pine wilt by serving as a carrier organism for pinewood nematode, Bursaphelenchus xylophilus. This nematode blocks the water conducting system of pine trees, resulting in brown leaves of specific branches or entire tree. The pine sawyer beetles spread the nematode from infected plants to other healthy pine trees. Nearly all species of pine are susceptible to beetles.

Pine Bark Beetle
Another pine beetle is the dendroctonus species, which feeds voraciously on the barks of pine trees. Usually, it attacks the middle and upper portion of the trunk. This pine tree beetle burrow the bark and create tunnel to reach the center of the trunk. Once, it reaches the meat of the tree, the adult female lays eggs. The eggs hatch into larvae, which then feed on the barks. The larvae pupate and complete their life cycle in the infested pine tree. Later, they emerge as matured adults from the tree holes.

Some of the notable signs that indicate bark beetle infestation are yellowing or browning of the foliage, small holes on the tree trunk and accumulation of tube-shaped masses around the holes. Since the bark beetles reside underneath the bark of pine tree, they are hardly identified. Mild infestation with a few number of beetles may weaken the pine tree. However, if these beetles are not identified earlier, they continuously feed and breed, leading to a significant increase in the number. Severe infestation can cause death of the entire tree.

Southern Pine Beetle
Southern pine beetles infect the pine trees independently or in association with engraver and turpentine beetles. Similar to the bark beetle, southern beetles bore through the bark and feed on the plant sap. The signs of southern pine beetles attack are occurrence of pitch tubes or red boring dust on the bark or at the base of the tree. The female lays eggs, which after hatching continue to feed on the bark and sap. Overall, these affect the water and nutrient assimilation, leading to weakening and finally, death of the pine tree. Southern pine beetles have the potential to kill a pine tree within a few days after infestation.

In order to prevent pine tree beetles, the best method is to keep the trees healthy. Regular pruning of pine trees is advisable in order to remove the weak and diseased parts of the plant. Doing so will help in controlling pests and spreading of diseases to the remaining portions of the tree. If necessary, you can spray appropriate insecticides to the diseased pine tree after consulting an horticulturist.