Pine tortoise scale feeding results in yellowing of needles, stunted needle growth, and even death of pines under extensive populations. In general, young pine trees are more susceptible to pine tortoise scale than older (mature) trees. In addition, foliage closer to the ground tends to support higher populations of pine tortoise scale than foliage higher in the tree canopy. Pine tortoise scale produces copious amounts of honeydew, a clear sticky liquid that serves as a growing medium for black sooty mold. Entire pine trees may appear blackened from black sooty mold as a consequence of heavy infestations of pine tortoise scale.
A forceful water spray applied twice per week will quickly dislodge/remove the nymphs and mature females from infested pine trees. Insecticides that can be used to suppress populations of pine tortoise scale nymphs include: acephate (Orthene, Bonide Systemic Insect Control), acetamiprid (TriStar; Ortho Flower, Fruit & Vegetable Insect Killer), bifenthrin (Talstar), cyfluthrin (Tempo, BioAdvanced Vegetable & Garden Insect Spray), dinotefuran (Safari), imidacloprid (Merit), insecticidal soap (potassium salts of fatty acids), and horticultural oils (petroleum, mineral or neem-based). These insecticides must be applied when nymphs are present to obtain maximum suppression of pine tortoise scale populations and subsequently alleviate future problems. (Raymond Cloyd)