Christmas tree pests and weeds of different pests, most of which cause cosmetic damage to the trees, important in the Christmas tree industry. The balsam woolly adelgid ("Adelges picae") are small soft-bodied insects which attack the Fraser fir. The insects appear as white, woolly spots on the tree and are fatal to the fir if left untreated. The woolly adeligid was native to central Europe where it affected the silver fir; it was introduced to the United States, where it has no known native predators, before 1900. Balsam twig aphids ("Mindarus abietnus") are another type of tree pest which affects fir and spruce trees in
Tree of Life (craft) luxurious pieces began to be produced. This type of work is typified by the tree of life, especially those that are not religious in function. These non-religious trees have themes such as death or spring. The construction of clay tree sculptures with the Biblical theme of the Garden of Eden began in Izucar de Matamoros in Puebla State and spread to other areas, particularly to Metepec, Mexico State, which distinguished their trees by painting them in bright colors. The tree sculptures have become emblematic of this municipality, and are part of a clay sculpture tradition found only here. Other common