Pine Tree Insect Pests
- Scale insects are so named for their scaly, shell-like exoskeleon. Scales are very small and inconspicuous creatures. Their tiny mouthparts pierce tender, young pine needles and branches, slurping up the nutrient-rich plant fluids. The pine tree branches wilt from starvation. Some scale species produce honeydew, a sooty, sticky substance that coats pine needles and inhibits proper photosynthesis. While pine tree death by scales is rare, scales might weaken the health of the tree and expose the tree to more serious damage from pests and environmental distresses, such as drought. Examples of common scale insects include the pine tortoise scale, spruce bud scale and Fletcher scale.
- Of all pests, wood-boring insects wreak the most harm to pine trees. An infestation may not be evident until the tree shows signs of deep decline or death. Wood-borers and root-borers lay their eggs beneath the bark of the tree; once hatched, the larvae chew through the savory cambium inside. Globs of pitch may form over the bore holes, concealing the presence of these pests until the tree finally languishes from distress. Besides the obvious physical effects of the tunnels into the sensitive cambium layer and the nutrient-rich xylem layer, borers might introduce bacteria into the sensitive internal section of the tree. White pine blister rust and other blights can cripple and kill the tree. Wood-boring insects common to pine trees include the Southern pine beetle, black turpentine beetle, Ips engraver beetle and Ambrosia beetle.
- Defoliating insects devour the green needles of pines. Some defoliators are not particularly discriminating, and will consume tender young terminal shoots and buds, as well. While rarely fatal to the tree, a severe infestation may inflict enough damage to stunt the growth of the tree or disfigure the aesthetic shapeliness of the branches. The European pine sawfly feeds on old growth needles, preferring the mugho, Scots and red pine trees. Weevils such as the Deodar or white pine weevil feed on the bark of the tree's main terminal shoot.
- Pine tree insects are rarely primary pests, or the first cause in the decline and death of the tree. Insects are secondary pests, as they tend to seek already stressed or damaged trees. Environmental extremes such as drought, flooding, improper soil, improper care, mechanical damage, or extreme cold or heat weaken the tree and make it susceptible to insect pest infestations. The best defense against insect problems is a healthy tree protected from environmental and physical injury.
