Bugs That Infest Pine Trees in Utah

• The sturdy, prized pines in your home landscape, which offer strong visual impact with needle-like foliage and cones, are open to a slew of potentially destructive pests. To maintain a home gardening space free of cosmetic damage and diminished health, the primary method of control is providing consistent care for vigorous trees. Grow pines in areas that offer full sun exposure and well-drained soil.

European Pine Shoot Moth

• European pine shoot moths (Rhyacionia buoliana) display dark heads and pale-yellow bodies in their larval stage, when they measure up to 1/2 inch long. Adults display orange-red bodies with silver stripes, and their bodies measure approximately 0.8 inches across the wingspan. European pine shoot moths in Utah typically target Austrian and mugo pines, among other two-needle species, according to the Utah State University Cooperative Extension. The larvae tunnel into new growth of leaves and buds, resulting in wilting of buds, the development of a gummy substance (gummosis) on dead bud tips and growth problems. Though extreme damage diminishes tree health, these shoot moths don't kill pines. For control of this Utah tree bug infestation, gardeners should apply an insecticide with an active ingredient like spinosad or carbaryl.

Black Pine Aphid

• Black pine aphids (Cinara species) are large aphids with black bodies and white markings. Cinara watsoni, for example, measure approximately 1/8 inch long, whereas many aphids measure just under 1 inch. Most infestations appear on ponderosa pines and Austrian pines in Utah, though they're not known to cause severe damage. Black pine aphids suck plant sap from trees while excreting honeydew, a sticky, sugary substance. As honeydew drips onto tree surfaces, it encourages the development of sooty mold fungal infection. Sooty mold creates black mold that covers the bark, resulting in a secondary disease. To control the black pine aphids in Utah pine trees, gardeners can push them from trees with a forceful stream of water. In extreme cases, the use of horticultural oil or an insecticide containing the active ingredient permethrin are effective chemical treatments, according to the Utah State University Cooperative Extension.

Pine Needle Scale

• Pine needle scales (Chionaspis pinifolia) are tiny, measuring approximately 0.1 inches long, and display white, wax-covered bodies. This pest problem primarily targets Scotch pines and mugo pines. Scales are sucking bugs that remove and eat tissue fluid from pine trees during the larval stage. Pine needle scales display armor-like structures over their soft bodies. Horticultural oil applied to crawlers is a reliable, low-toxicity method of dealing with them. For severe infestations, insecticides with the active ingredient carbaryl or cyfluthrin help control the situation, according to the Utah State University Cooperative Extension.