Consult the labels for dosage rates and safety precautions. Pine twig gall scale, Matsucoccus gallicolus . This scale attacks several species of pines. Ornamental plantings of pitch pine are often severely weakened or killed by this scale. It has a single generation per year and overwinters as eggs.
Young nymphs hatch and settle on the developing new twig growth in spring.
They become enveloped by swellings of the bark and, therefore, are very inconspicuous until trees are heavily infested. Control by use of insecticides has not been successful and no effective natural enemies are known. Pine webworms, Tetralopha robustella and T. melanugrammos . Seedlings of red pine and white pine are sometimes infested with caterpillars that web together the leaves and frass, live in tubes within the mass, and feed on the needles. Little is known of their life histories.